Update TSDS disk space reduction percentage (#94549)

docs/reference/data-streams/tsds.asciidoc

@@ -5,7 +5,7 @@ A time series data stream (TSDS) models timestamped metrics data as one or
 more time series.
 
 You can use a TSDS to store metrics data more efficiently. In our benchmarks,
-metrics data stored in a TSDS used 44% less disk space than a regular data
+metrics data stored in a TSDS used 70% less disk space than a regular data
 stream.
 
 [discrete]