The first column is for the fluence ( one count for 4.03 10^^8 p/cm2).
The second one is the SEU rate for 756 (12*63) flip-flops.

471 55
941 100
1697 207
2488 305
3356 397
4586 497
5588 601
6542 701
7691 804
8951 899
10047 999
11062 1123
11982 1200
12759 1302
13831 1398
15101 1510
16231 1604
17379 1700
18445 1800
19505 1902
20603 2000
22124 2118
23090 2200