From the Sentry: Earth Impact Monitoring page,
33680 listed Impact Probability data [using Unconstrained Settings]
were imported into a spreadsheet [ Open Office Calc ]
and added*.
The sum was 0.1743 [17.43%] which represents the probability of impact
by one or more of the 33680 listed objects over the next hundred years.
Worthy of note are 3373 objects [more than 10%] with impact energy
greater than one Megaton TNT, enough to demolish a city.
* students of Statistics will note the addition of event probabilities
is merely an approximate method of estimating the probability of occurrence
of at least one event, but also that the resulting error is small enough
to be negligible where (as in this case) the sum of the probabilities is small.
