How to set/clear count property after using dataview rowfilter

Hi Everyone,
May I have your help.
I have a bit of experience of Ui Path and VB code. I would like to know how to set/clear count property after using dataview rowfilter.

I have scape data table from some website and I already change datatable type to dataview via using dt.defaultview
I already using dv.count after rowfilter, the result is ok, but when I using loop to count again. The result is double.

For Example, I already using rowfilter that have word “Start” in Column 1 and using dv.count. I got result is 2. after 15 Second using delay for loop, it scrape data again, but I got result is 4. This means, dv.count is 2+2.
Can anyone help or suggest me how to set dv.count to 0 after the end of loop.

Thank in advance.