I believe that "Last Updated" refers to updates to the app itself, not the stats.
I'm pretty sure Google updates the downloads once a day and it's in brackets.
- 1-5
- 5-10
- 10-50
- 50-100
- 100-500
- 500-1000
- 1,000-5,000
- 5,000 - 10,000
- 10,000 - 50,000
- etc...