Analyzing click rate between 2 variables

I am a bit new to this and I have what I believe is a basic question. For one year I have been sending the same email every two weeks. The variable I want to analyse is the language( English and French). I would like to know how important is the difference of click rate between English and French. I already have all the data, I am just not sure what is the best test to use for this. Any help?

Thanks,

Daniel