I added four to my roster in 2015 for a total of 61/100. I took a vacation in Puerto Rico, adding #43 SJU. On that trip I also added #29 TPA and #36 MCI via connections. I didn't go out of my way to choose those connections; they happened to be at the times that fit my schedule best. The fact that they added extra airports to my history was simply a bonus.

Finally, I took a short vacation via #76 TUL (yes, really).
In 2016 I think I'll add a few more. I'll probably find myself transiting DAL at some point now that the Wright Amendment is history and WN is scaling up there. And I'll probably add another Hawaiian airport for a vacation late in the year.
* Using the FAA's rankings published 9/22/15 based on CY 2014 traffic.