We have in excess of 25,000 formal school visits a year at the Calgary Zoo. We have 1.2 million visitors overall.
We hope everyone who visits the zoo will take something beneficial away from it. A lot of that is not necessarily through formal education, but merely by the experience of getting the opportunity to see animals, to get close to animals and to smell them. You described the experience at the aquarium. There is a very real difference between being up close and personal to a living animal. I think it sensitizes people to conservation messages, which TV and classroom-based education really can't.
We approach conservation education on a whole bunch of levels, such as formal teaching programs in the zoo and keeper talks throughout the day.
Kevin might be able to talk about the numbers of people we think are exposed to educational experiences at the zoo.