Airline accident ratings
Plane crashes don't happen all the time. There were only three major crashes that I recall. Sept-11 (out of our control), Hudson River, and the Buffalo crash. Even though I do not like to fly, statistically flying is still safe for commercial airlines.
According to that site, if the data is accurate. There were 29 fatal flights in North America, 140.59 million flights in North America from Jan `89 to Dec `08.
29/140590000 = 0.000000206274
or 0.000021%
or 0.2ppm flights. (Part per million)