In '09, Houston threw the ball 747 times for 525 completions. Cleveland caught 104 passes, good for 19.8% of Houston's completions and 13.9% of their pass attempts.
In '10, Houston threw the ball 484 times for 298 completions. Cleveland caught 57 passes, good for 19.1% of Houston's completions and 11.8% of their pass attempts.
To your point, he was the Cougars leading receiver in '09 but not in '10; however, I would say that was as much caused by missing two games as anything else. Edit: I double-checked and Cleveland participated vs. Texas Tech and accumulated zero stats. He isn't listed as having participated vs. Mississippi St.