I recently found
this AAMC website that provides USMLE Step 1 and Step 2 CK Scores of (2015-2016) first-year residents by specialty. You can look up your desired specialty and then cross check your Step 1 score with your Step 2 score. The chart tells you how many applicants (and what percentage) successfully matched with those Step numbers in your desired specialty - helpful for predicting application success in a chosen field. Check it out.