OK, I've done some more testing and all appears to be working now: I've posted a sortable chart of data about daytime (i.e. commuting and living/working) population trends in Mass. cities and towns, based on U.S. Census data.
The chart is at www.pedestrianfriendly.com/data1.php
Almost one-third of employed Framingham residents also work in town. Marlboro is very close to that. Maynard, once the home of Digital Equipment. Corp., is now at 17%. And Bellingham is just 8.3%.
Framingham's daytime population rises 14% compared to its full-time residential population, while Marlboro's is up 37%. Bellingham's slips 2.1%, while Northboro's drops 10%.