Pat Leahy, Executive Director of the American Geological Institute, told the state geologists' annual meeting this morning that "the 2008-2009 academic year saw a sharp 8% increase in the number of geosciences undergraduates enrolled in U.S. institutions, to a total population of 22,191."
AGI subsequently released the latest issue of Geoscience Currents, which documented these numbers [right].
I've contacted AGI for Arizona-specific data.