Calculating correlation between intermittent events and complete data

I have two sets of data. One shows an event every few years, such as 2002, 2007, and 2009. I then have another set of data that shows an activity count for every year, i.e. 2002, 2003...2009, 2010. Is there a way to run a correlation test between these two, to see if the level of activity correlates to the events?

As an example:

Legislation was passed on 2002, 2007 and 2009. We then have the count of complaints per year:

Year, n_complaints
2002, 100
2003, 50
2004, 75
2005, 60
2007, 120
2008, 30
2009, 75
2010, 110


I then want to answer the question: How does the passage of a bill correlate to the number of complaints? Is there a correlation test to answer this?