Space Forum / Shuttle / March 2004

NASA has stated that one of the most significant dangers to the shuttle is
collisions with space debris or micrometeors. While docked at the ISS, the
shuttle must be turned into the path of any oncoming space debris or
micrometeors (which have already caused pits in the shuttle's windows.) At
Hubble, the shuttle can orient itself away from any oncoming debris. It has
been calculated that on the last shuttle flight to the station the probability
of a fatal collision with micrometeors or space debris was 1 in 250; on the
last mission to Hubble, it was 1 in 414.

This is from the save hubble website. Are the risk numbers accurate?