MATH-1551: Track changes.

Closes #157.
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 1b4ce81..ec8c680 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -54,6 +54,9 @@
     </release>
 
     <release version="4.0" date="XXXX-XX-XX" description="">
+      <action dev="erans" type="add" issue="MATH-1551" due-to="Allen Yu">
+        "Percentile": Partial support for weighted data.
+      </action>
       <action dev="erans" type="update" issue="MATH-1554">
         Remove package "o.a.c.math4.geometry".
       </action>