Note the year before, it was 606, which is where it's been for a while. It wasn't as high as 851 in the early 80s, when the population was nearly 1/3 lower as well as the number of guns owned.
Something is wrong with one of these two statistics. Besides the discontinuity, I seriously doubt we in the gun community wouldn't have noticed a 30% increase in the number of accidental gun fatalities.
Note, I'm not saying this preliminary 2011 number is wrong, just that I suspect something other than the real rate of accidents changed. Hmmm, there's not even any external event that would account for a 2010 to 2011 increase (i.e. the major spikes in purchasing were after Obama was first elected and after Newtown, things were back to something like "normal" in 2011 although sales just kept going up and up year to year each month).
ADDED: As those major increases in population and guns owned occurred, we worked really hard to get the accident rate down. Mandatory hunter safety courses, a general emphasis on safety in the now larger self-defense area, etc. etc. etc. The rate is still down due to the population increase, but....
Deliberate murders involving guns outnumber accidental killings some 36 to 1.
Note however that accidental automotive killings outnumber deliberate willful homicides using firearms. Odd that somehow the former garners little public concern.