You can't say, a few don't even know what  bitcoin is, some know what bitcoin is and don't even bother about it. Banks only like the concept of block chain technology, and most of them think that bitcoin is a bubble just like the housing bubble asset of 2005. A few banks are starting to think about developing their own crypto currency but I guess most of them will take a few years to implement it. So bitcoin is never of main concern for them because they think bitcoin cannot replace banks no matter what.