The table below shows the number of students from two different high schools who completed summer internships in each of five years. No student attended both schools.
| High school | 2008 | 2009 | 2010 | 2011 | 2012 |
|---|---|---|---|---|---|
| Foothill | 87 | 80 | 75 | 76 | 70 |
| Valley | 44 | 54 | 65 | 76 | 82 |
| Total | 131 | 134 | 140 | 152 | 152 |
What is the positive difference between the total number of students from Foothill High School and the total number of students from Valley High School who completed summer internships over all five years shown in the table?
