If you go to College Data’s College Search page. Under Entrance Difficulty, select Most Difficult. On results page with colleges, scroll to right under the column heading Financial Friendliness, sort by Merit Aid. This should give you a good idea of % receiving merit. For those that do give merit, go to individual college and right click on Money Matters. The resulting page will give you more detailed information on number receiving merit and average award as well as a direct link to the Financial Aid site for the college.
If the field Merit % is blank, I would assume no merit is provided.