The IMP Scale
  0 -   10 =  0            750 -  890 = 13
 20 -   40 =  1            900 - 1090 = 14
 50 -   80 =  2           1100 - 1290 = 15
 90 -  120 =  3           1300 - 1490 = 16
130 -  160 =  4           1500 - 1740 = 17
170 -  210 =  5           1750 - 1990 = 18
220 -  260 =  6           2000 - 2240 = 19
270 -  310 =  7           2250 - 2490 = 20
320 -  360 =  8           2500 - 2990 = 21
370 -  420 =  9           3000 - 3490 = 22
430 -  490 = 10           3500 - 3990 = 23
500 -  590 = 11           4000 - more = 24
600 -  740 = 12