The list is for candidates

Your list is for the candidates 2013, and there are more than 40 students for large states (CA, TX). WA has 40 candidates - I guess.

Here is the list for 2013 Presidential Scholars Semi-finalists:
    http://www2.ed.gov/programs/psp/2013/semifinalists.pdf

There are more than 12 semi-finalists in large states (CA, TX), but less than 12 for small states (WY, IN). This makes sense to me. I know a few great kids with SAT 2390-2400, but not in the list of the semi-finalists (they went to HYPSM). It may be due to the fact that the award (semi or final) does not give any benefits to college admission, and no financial benefit (since the semi-finalists are announced in April, 2013), so some did not put enough effort in applying it.