Of the 199.0 million persons 1 year old and over living in the United States in March 1970, 36.5 million, or 18.4 percent, had been living at a different address in March 1969, according to estimates from the Current Population Survey conducted by the Bureau of the Census. Of the 36.5 million persons who had moved between March 1969 and March 1970, 23.2 million had moved within counties, 13.3 million between counties--6.3 million within the same State, and 7.1 million between States. An additional 1.6 million had been living abroad in March 1969. According to the 23 annual surveys conducted since 1948, the percentage of the population who changed address during the preceding 12 months has ranged from 18.3 to 21.0, a relatively small variation. With the exception of persons who moved from, but returned to, their 1969 address during the survey year, the survey provides an estimate of all persons who moved during the year. It does not, however, provide an estimate of the total number of moves during the year, since the movers may have moved more than once.