I do not know the figures except that in the past, UWSOM students produced slightly lower Step 1 scores than the national average, and slightly higher Step 2 scores than the national average. A student on the curriculum committee mentioned this December that last year's Step 1 scores equalled the national average, as a result of a push by the school leadership to teach more classes "to the boards." UWSOM gives approximately one month of lecture-free time for Step 1 study, while Step 2 study time is up to the student (i.e., 3rd years have 6 weeks of elective time that they can fill up with elective clerkships or use as study time for the Step 2 at their discretion).
~Kalyx