As I understand it the US News rankings adhere to the same principle as the ABA = a straight average, no matter the degree of improvement, which makes sense because the new April 1 rankings follow the recently released ABA data. I do not believe they'd transform these data in any way, they are purely inputs.
Additionally, it has been my experience that a school will deny a candidate based on these numbers alone. I myself had a 12-point jump the second time around, a reasonable explanation, attended a top undergrad institution while taking a broad and range of challenging courses, and have significant and meaningful research and work experience. Thus far, however, I have found no luck with these schools placing more weight on the second score. It definitely is a numbers game to these schools, which most certainly is a consequence of rankings. The only truly subjective measure that will change that is, of course, minority status.