Not to belittle the lives lost, but only 4 have been in the last 20 years, 10 since 1980. And half of the 51 were in a practice or test session, not an actual race so those are largely attributed to something else besides racing conditions.
And for the record, Nascar has had 28 fatalities, with the last one being Dale Earnhardt in 2001. But once again, very similar to F1, most of those occurred in the 50s, 60s and 70s. Considering how many more accidents occur in Nascar and the fact that these guys are driving normally 180+ mph door-to-door, its amazing there aren't more fatalities.