Update docs/api/covidcast-signals/indicator-combination.md

Co-authored-by: george <[email protected]>

Author: dshemetov

docs/api/covidcast-signals/indicator-combination.md

@@ -22,7 +22,7 @@ calculated or composed by Delphi. It is not a primary data source.
 ## Statistical Combination Signals
 
 * **Earliest issue available:** May 20, 2020
-* **Number of data revisions since 19 May, 2020:** 1 (see [data revision docs](../covidcast_changelog.md#indicator-combination))
+* **Number of data revisions:** 1 (see [data revision docs](../covidcast_changelog.md#indicator-combination))
 * **Date of last data revision:** June 3, 2020 (see [data revision docs](../covidcast_changelog.md#indicator-combination))
 * **Available for:** county, msa, state (see [geography coding docs](../covidcast_geography.md))
 * **Time type:** day (see [date format docs](../covidcast_times.md))