Graded NH Races - comparison

I always thought that there were way more graded races in Ireland than UK, always a grade 1 over the jumps in Ireland each sunday. So I analysed:

Ireland       
Row Labels    Count of prize money 1    Average of prize money 1
1    42    £75,082
2    36    £26,655
3    59    £30,879
Grand Total    137    £43,320
       
United Kingdom       
Row Labels    Count of prize money 1    Average of prize money 1_2
1    41    £102,443
2    76    £41,059
H    59    £68,645    - premier handicaps
List    50    £19,447
Grand Total    226    £54,615

If you take grade 3 Ireland equating to Listed level then the number of races are broadly the same,. Another surprise to me, the average win prize money in UK is actually better
In which case, why arn't there more quality UK horses running for the better prize money?