Improve sentence clarity

Author: matthurne

source/applications/aggregation.txt

@@ -169,8 +169,8 @@ The aggregation operation in the previous section returns a
 - ``ok`` which holds the value ``1``, indicating success, or another value
   if there was an error
 
-As a document, the result is subject to the current :ref:`BSON
-Document size <limit-bson-document-size>`, which is 16 megabytes.
+As a document, the result is subject to the :ref:`BSON
+Document size <limit-bson-document-size>` limit, which is currently 16 megabytes.
 
 Optimizing Performance
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