diff --git a/contrib/udfs/README.md b/contrib/udfs/README.md
index 23ece7d..844341c 100644
--- a/contrib/udfs/README.md
+++ b/contrib/udfs/README.md
@@ -1,6 +1,6 @@
 # Drill User Defined Functions
 
-This `README` documents functions which users have submitted to Apache Drill.  
+This `README` documents functions which users have submitted to Apache Drill.
 
 ## Geospatial Functions
 
@@ -201,7 +201,7 @@
 
 ### Time Bucket Functions
 These functions are useful for doing time series analysis by grouping the data into arbitrary intervals.  See: https://blog.timescale.com/blog/simplified-time-series-analytics
--using-the-time_bucket-function/ for more examples. 
+-using-the-time_bucket-function/ for more examples.
 
 There are two versions of the function:
 * `time_bucket(<timestamp>, <interval>)`
@@ -225,7 +225,7 @@
 This function is based on Niels Basjes Java library for parsing user agent strings which is available here: <https://github.com/nielsbasjes/yauaa>.
 
 ### Basic usage
-The function `parse_user_agent()` takes a user agent string as an argument and returns a map of the available fields. Note that not every field will be present in every user agent string. 
+The function `parse_user_agent()` takes a user agent string as an argument and returns a map of the available fields. Note that not every field will be present in every user agent string.
 
 The basic function signature looks like this
 
@@ -243,7 +243,7 @@
 ### Analyzing the User-Agent
 
 ```
-SELECT parse_user_agent( columns[0] ) as ua 
+SELECT parse_user_agent( columns[0] ) as ua
 FROM dfs.`/tmp/data/drill-httpd/ua.csv`;
 ```
 The query above returns:
@@ -287,7 +287,7 @@
 ```sql
 SELECT parse_user_agent( `user_agent`, 'AgentName` ) as AgentName ...
 ```
-which will just return the requested field. If the user agent string is empty, all fields will have the value of `Hacker`.  
+which will just return the requested field. If the user agent string is empty, all fields will have the value of `Hacker`.
 
 ### Analyzing the User-Agent Client Hints
 
@@ -380,7 +380,7 @@
 The improvement after adding the Client Hints is evident.
 
 ## Map Schema Function
-This function allows you to drill down into the schema of maps.  The REST API and JDBC interfaces will only return `MAP`, `LIST` for the MAP, however, it is not possible to get 
+This function allows you to drill down into the schema of maps.  The REST API and JDBC interfaces will only return `MAP`, `LIST` for the MAP, however, it is not possible to get
 the schema of the inner map. The function `getMapSchema(<MAP>)` will return a `MAP` of the fields and datatypes.
 
 ### Example Usage
@@ -419,7 +419,7 @@
 # Threat Hunting Functions
 These functions are useful for doing threat hunting with Apache Drill.  These were inspired by huntlib.[1]
 
-The functions are: 
+The functions are:
 * `punctuation_pattern(<string>)`:  Extracts the pattern of punctuation in text.
 * `entropy(<string>)`: This function calculates the Shannon Entropy of a given string of text.
 * `entropyPerByte(<string>)`: This function calculates the Shannon Entropy of a given string of text, normed for the string length.
@@ -431,7 +431,9 @@
 * `width_bucket(value, min, max, buckets)`: Useful for crafting histograms and understanding distributions of continuous variables.
 * `kendall_correlation(col1, col2)`:  Calculates the kendall correlation coefficient of two columns within a dataset.
 * `regr_slope(x,y)`: Determines the slope of the least-squares-fit linear equation
-* `regr_intercept(x,y)`: Computes the y-intercept of the least-squares-fit linear equation
+* `regr_intercept(x,y)`: Computes the y-intercept of they least-squares-fit linear equation
+* `percent_change(x,y)`:  Computes the percent change between `x` and `y`.  Handles nulls and
+  zero values.
 
 
 [1]: https://github.com/target/huntlib
@@ -443,4 +445,4 @@
 * `getHostName(<IP address>)`:  Returns the host name associated with an IP address.
 * `getHostAddress(<host>)`:  Returns an IP address associated with a host name.
 * `dnsLookup(<host>, [<Resolver>])`:  Performs a DNS lookup on a given host.  You can optionally provide a resolver.  Possible resolver values are: `cloudflare`,  `cloudflare_secondary`, `google`, `google_secondary`, `verisign`, `verisign_secondary`, `yandex`, `yandex_secondary`.
-* `whois(<host>, [<Resolver>])`:  Performs a whois lookup on the given host name.  You can optionally provide a resolver URL. Note that not all providers allow bulk automated whois lookups, so please follow the terms fo service for your provider.
\ No newline at end of file
+* `whois(<host>, [<Resolver>])`:  Performs a whois lookup on the given host name.  You can optionally provide a resolver URL. Note that not all providers allow bulk automated whois lookups, so please follow the terms fo service for your provider.
diff --git a/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/DistributionFunctions.java b/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/DistributionFunctions.java
index 0b4b623..fd18fd4 100644
--- a/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/DistributionFunctions.java
+++ b/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/DistributionFunctions.java
@@ -327,4 +327,40 @@
       ss_xy.value = 0;
     }
   }
+
+  /**
+   * This UDF calculates the percent change between two numeric columns.
+   */
+  @FunctionTemplate(names = {"percentChange", "percent_change"},
+      scope = FunctionScope.SIMPLE,
+      nulls = NullHandling.NULL_IF_NULL)
+  public static class PercentChangeFunction implements DrillSimpleFunc {
+    @Param
+    Float8Holder oldHolder;
+
+    @Param
+    Float8Holder newHolder;
+
+    @Output
+    Float8Holder resultHolder;
+
+    @Override
+    public void setup() {
+      // No op
+    }
+
+    @Override
+    public void eval() {
+      double v1 = oldHolder.value;
+      double v2 = newHolder.value;
+
+      if (v2 == 0) {
+        resultHolder.value = 0;
+      } else if (v1 == 0) {
+        // No op
+      } else {
+        resultHolder.value = (v2 - v1) * 100.0 / v1;
+      }
+    }
+  }
 }
diff --git a/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestDistributionFunctions.java b/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestDistributionFunctions.java
index b7b8b53..34f9ee0 100644
--- a/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestDistributionFunctions.java
+++ b/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestDistributionFunctions.java
@@ -105,4 +105,63 @@
         .baselineValues(1400.2322223740048)
         .go();
   }
+
+  @Test
+  public void testPercentChange() throws Exception {
+    String query = "SELECT percent_change(100, 150) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(50.0)
+        .go();
+
+    query = "SELECT percent_change(200, 100) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(-50.0)
+        .go();
+
+    query = "SELECT percent_change(200, null) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(null)
+        .go();
+
+    query = "SELECT percent_change(null, null) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(null)
+        .go();
+
+    query = "SELECT percent_change(null, 200) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(null)
+        .go();
+
+    query = "SELECT percent_change(200, 0) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(0.0)
+        .go();
+
+    query = "SELECT percent_change(0, 34) as delta";
+    testBuilder()
+        .sqlQuery(query)
+        .unOrdered()
+        .baselineColumns("delta")
+        .baselineValues(0.0)
+        .go();
+  }
 }