Registration reports

 Hi,i have a question in regards to 2 of the reports under Registration Reports.

1)Summary of Program Registration and 2) Program Registrant Profile

I am just looking for a total count of people who have registered under my programs.

Report 1 gives me 'registration count' and 'unique registration count'.  I'm assuming the registration count includes duplicates whereas unique registration count doesn't.  

Report 2 allows me to see the number of records based on a specific program. (this report includes duplicates)

But after removing duplicates from Report 2 and comparing with Report 1 under 'unique registration count', the numbers don't match. Am I interpreting these fields incorrectly?