Los Angeles County, California, keeps a running total of how many registered voters there are in each qualified party on its web page. See here.

Between July 7 and July 26, the number of registered voters in the county declined, probably because the county is doing a purge. The number of registered voters in each qualified party (except the Peace & Freedom Party) declined between those dates, and the number of registered independents also declined. However, the number of Peace & Freedom Party registrants increased by 2,594 voters. This is because the party is doing a registration drive.