Hi Infinito.
Ok here's what happens. From the FAQ:
If multiple people tie for a place, the percentages for those places will be added up and divided by the number of people who tied for the place. For example, if three people tie for 2nd place, the percentages for 2nd, 3rd and 4th place will be totaled up and divided by three. Each player would receive the same amount. 5th place will then get the correct 5th place percentage.
So basically you tied with 11 other people for 23rd. So WGT will take prize values 23 through 33 (that's 11), add them all up, divide by 11, and that's what you get.