Chris and Olivia each took six tests, each scored out of a maximum of 100 points. Chris averaged 80 on the six tests. Olivia scored 2 points lower than Chris on the first test, 5 points higher on the second test, 1 point lower on the third test, 4 points higher on the fourth test, 3 points lower on the fifth test, and 3 points higher on the sixth test. What is the difference between Olivia's average and Chris's average on these six tests?