For Memphis, the impetus was the 2000 census figures and tax data.

The latter are taken from a variety of sources, including tax data and surveys on consumer expenditure.

This is the method used by most funds that provide tax data to investors.

Selected tax data is released as economic data for research.

Giving to charities continues at its historic level of about 2 percent of income, tax data show.

The 2005 tax data did not include the 54,000 immigrants who settled in New Jersey last year.

Government agencies also are collecting information but much of it is tax data not available to the public.

But some said they needed access to private information, like tax data, to fight potential terrorists.

The tax data have it at 4 percent in both years.

Then, with the same federal tax data, it calculated what percentage of those assets the households have given to charity, on average, in recent years.