clickhappy

I want to see my membership growth in a chart. The only data I have is date a member signed up.
so it'll say:
member_name1 signed up 12/01/2008
member_name2 signed up 12/01/2008
member_name3 signed up 12/02/2008
member_name4 signed up 12/02/2008
member_name5 signed up 12/02/2008

I have over 8,000 members so I dont want to do this by hand, Is there a program that will take this data and tell me how many members I got on that day. AND then give me a line chart, so I can see growth?

thanks