need a proportional test for differences in a small series

[Gartland, Myles]

I am stuck on how to determine if there is a statistical difference between two time series of aggregate percentages. Two groups (n=~80) were surveyed each year for 7 years, and their aggregate median cost percentage was reported.   From 1993 to 1999-   Group A median percentage- 51.91%. 52.73% ......54.17% Group B median percentage- 60.13%, 57.03%, .....67.30%   This is all the information I have other than the sample size for each year for each group (they are about n=80 per group per year). I do not have percentages from each individual respondent, just an aggregate percentage for the group.   I assume I can call these proportions since they are stated in percentages.   My hypothesis question is if group B is statistically higher and increasing at a statistically higher rate then group A.   However, I am stuck on how to test. I would have assumed a chi-square, but my limited background in chi-square (if that is appropriate) cannot figure out what to do.   Any ideas?     Myles Gartland