I need listing for ?Mandatory Professional Exams" (certification and tests) in USA.

?Mandatory Professional Exams? means, something that an individual has
to do to keep / maintain his job. It is not something just nice to
have. Examples of Mandatory Professional Exam are:
- Financial - Series 7 
- Legal ? State Bar Exam 
- FAA 
- Real Estate 
Etc. 

Example of something nice to have, which I don?t care about are: Java
certification, networking, driving license etc.

>> What are the top 10 ?Mandatory Professional Exams? in USA by volume
(number of people appearing per year), where question makeup is mostly
non-descriptive (example: select one of the following, true/false,
select all of the following, fill in the blanks, etc)? If the exam is
conducted at state level (example bar exam), please provide
information for top 5 states.