Corrects typo in README.md

README.md

@@ -4,7 +4,7 @@ Rationale
 `shputil.py` was born out of a need to modify large (>1GB) shapefiles
 that could not be easily or successfully managed in programs like QGIS.
 As an example QGIS was unable to perform a simple string
-search-and-replace on a file over 26000 records, remaining unresponsive
+search-and-replace on a file over 200,000 records, remaining unresponsive
 and consuming 100% CPU even after 10 minutes. By comparison `shputil.py`
 is able to perform the same operation, using `replace-field-values`, in
 under 90 seconds.