Call to Raise ratio?

I just finished playing in a qualifier for the Paradise Poker Million Dollar Freeroll and finished 26th in a field of 970. Unfortunately, only the top 20 qualify.

Here are some of my stats for the tournament:

Games won: 7%

Showdowns won: 78%

Fold 64%
Check 13%
Call 15%
Bet 5%
Raise 2%

What jumped out at me when looking these stats was the small number of raises compared to calls.

I'm thinking that I wasn't aggressive enough. Then again, I finished in the top 3% of the field, beating out 944 other players. In addition, my cards were at best average. So, I had to be doing something right.

I'm wondering if there is an average call/raise ratio?

BTW

Thanks David, Ed, Dan and Mason. Without 2+2, there was no way I was finishing as high as I did with only 3 months of tournament experience.