fix: update

Author: 0xPoe

statistics.md

@@ -761,7 +761,7 @@ Used to control the concurrency of table or partition analysis — for example,
 
 #### `tidb_analyze_partition_concurrency`
 
-Used to control the concurrency for saving analyze results (writing TopN and histograms to system tables). The default value is `2`.
+Used to control the concurrency for saving analyze results (writing TopN and histograms to system tables). The default value is `2`. The default value is `1` for v7.4.0 and earlier versions.
 
 #### `tidb_analyze_distsql_scan_concurrency`