How representative are AMS membership surveys?

Data from annual National Science Foundation (NSF) surveys of graduate students and academic degrees granted can help in informing about how representative are AMS membership surveys. Statistics compiled by NSF indicate that the number of female graduate students in the atmospheric sciences has increased fairly steadily in 1972-73 academic year. The percentage of women has increased as well, with the sharpest increase coinciding with a drop in the number of male graduate students from 1993-2001, followed by a sluggish recovery till climbing back to pre-1993 levels with the onset of the 'Great Recession' in 2008. This increase in the percentage of women caused in part by a decrease in the number of men has been noted in some subsets of the 2005 AMS Member Survey data. The NSF data appear to support the representativeness of gender percentages based on the AMS survey data.