That claims that "that the lifetime risk of dying from an asteroid strike is about the same as the risk of dying in a commercial airplane crash".

It cites:

Impacts on the Earth by asteroids and comets: assessing the hazard:

http://www.nature.com/nature/journal/v367/n6458/abs/367033a0.html

I am very sceptical about that being true for those alive now:

We have been looking for things that might hit us for a long while now - and we can see much more clearly what the chances are for that period than by looking at the historical record. Also, that is apparently assuming no mitigation attempts - which also seems totally unrealistic.

Looking further:

http://users.tpg.com.au/users/tps-seti/spacegd7.html

...gives 700 deaths/year for aircraft - and 1,400 deaths/year for 2km impacts - based on assumption that one quarter of the human population would perish in such an impact.