Note
It looks like I went to the pool 117 times on my year pass - give or take a couple. December to May was 84 and June to December was 33, with April being the Month of the Cast with just 2 visits, and the months of Oct-Dec falling to 1 per month.
The per visit worked out to $343/117 = $2.93 vs. the $5.50 per single visit. Will try to get more out of the second part of the 2015 - try to go 2-3 times a week.