Don't have the data, but I'm willing to bet part of the reason is probably because a lot of people that didn't have an insurance plan before Obamacare now were forced to lest they pay the penalty; that's all the ACA really is anyway: a glorified mandate saying one had to pick private insurance from the government's limited marketplace or they'll be fined. Didn't solve dick...but hey, Obama did it so it must be progress!