Lets compare the whole trilogy to the Avengers.
Batman Begins - $206,852,432
TDK - $534,858,444
TDKR - $448,139,099
The Avengers - $623,357,910
Less people went to go see TDKR, and it made less money even though it was shown in more theaters.
The Avengers was shown in less theatres than TDKR, but made over $80 million more
TDKR was shown in 155 more theaters than The Avengers so more people went to see The Avengers and probably multiple times. And they came out the same year so aint none of that adjusted gross 
Face it breh. The country has spoken. And it proves what I've been saying from jump. Heath Ledger carried TDK. When he wasn't in it nikkas didn't care.