HEre is the list I was thinking of and going back to year 1900 and not counting last years:

PP/wins since 1900-2005

1. 12
2. 9
3. 8
4. 10
5. 12
6. 6
7. 7
8. 8
9. 4
10. 10
11. 3
12. 3
13. 4
14. 2
15. 3
16. 3
17. 0
18. 1
19. 0
20. 1

Obviously your more recent list seems more relevant but this might also have some releavance. There were large fields in the 1930s, 19 and 20 horse fields much of the time, it got way smaller in the 1940s, dont recall the 20s off the top. So...