Worldwide average TOEFL iBT score for 2010 = 80/120 (2009 = 79).
Grad student average = 84/120
Undergrad student average = 78/120
Professional licence applicant average = 83/120
Average male score = 81/120
Average female score = 81/120
To find your country's average 2010 TOEFL iBT score, follow this link or this link
Data courtesy of ETS