Streaming rate and data transfer

I am in Switzerland and listen to UK radio in the car on a BlackBerry to and from work. However, I found out today that the company's contract only gives 250MB per month of free data download (after that it is 0.09 Francs per additional MB). Please excuse my ignorance on such matters, but if I am listening at a streaming rate of 20kbps in parametric stereo for about a hour and a half a day, am I going to go over the monthly limit?