It's pretty easy if Access knows they're dates. If Access thinks they're
just random strings of numbers, it takes an extra step.
Since you said the dates are in various formats, and I kind of figure your
column has all the same format setting -- not very certainly, but it's the
likely supposition -- let's assume the format setting is text, and Excel
doesn't know that column has dates in it. So first you have to get Excel to
know what dates are represented there. Set up a "helper" column to the right
that uses the DATEVALUE function. If all your text dates are in column C,
let this first helper column (in col M, let's say) has the function
=DATEVALUE(C2) in M2. That means M has not a text value but a real Excel
date value in it corresponding to what's in col C.
Now in col N put =YEAR(M2); thus in col N is the year represented by the
date in col C.
To determine how many of those say 2002, for instance, use the formula
=COUNTIF(N,2002).
I don't use COUNTIF much, so take this with a grain of salt -- look it up,
check it out with other Excel jocks, test it for yourself etc.