PSAT score improvement per year

Hi, everyone. I’m interested in how much your PSAT scores went up, down, or remained stagnant from year to year. Did it go up by the same amount each year? How much prep did you do? I’m wondering if there is an approximate amount of points by which people improve their scores each year which might be true for almost everyone.

I’m in the Class of 2018 and thus I took the old PSAT the first year, but I converted that to the new PSAT here: https://collegereadiness.collegeboard.org/pdf/2015-psat-nmsqt-concordance-tables.pdf

Freshman year (minimal/no prep): RW/M: 660/610 Total: 1270 Selection Index: 193
Sophomore year (moderate prep): RW/M: 720/660 Total: 1380 Selection Index: 210
Junior year (intense prep): RW/M: 750/690 Total: 1440 Selection Index: 219

Thanks!

Class of 2018 here too:
Freshman year: (minimal prep): RW/M 710/710 Total: 1410 (yes I’m aware those don’t add up, I’m going off the concordance tables for a score of (R/W/M 68/65/68 = 201). SI: 213
Sophomore year: (minimal prep): RW/M 750/710 Total: 1460 SI: 221
Junior year: (moderateish prep… I tried) RW/M 760/740 Total: 1500 SI: 226