The CBS interval changed in the summer of 2013. It used to be longer....24months/15k miles. But starting with the July 2013 build date...BMW changed the CBS interval to 12 months/10k miles.
You don’t give a model year for your f02 so we have to assume that it was probably built prior to July 2013 since it had the longer CBS interval.
Here’s a link that has the CBS interval change info:
https://f10.5post.com/forums/showpos...08&postcount=1