Significance testing over time on frequency count

Hi all,

Not sure which test I should be using. I have five years of data from one city that lists all the individuals and if their income is low, medium, or high.
If I want to test if there is a significant change over time on the number of people under each category (low, medium, or high), should I be using Chi square test?
I.e. is there significant change in the number or percentage of individuals who has high income in that city.

Thanks in advance.


Not a robit
It seems like you should be implementing time series data with the dependent variable being a rate, then looking for patterns or changes in slope. Also, do you have actual income data, that would be more telling.