 From 1940 to 1990 Austin's population grew at an average rate of 40 percent per decade, from 87,930 to 472,020.By 2000 the population was 656,562.The city's corporate area, which between 1891 and 1940 had about doubled to 30.85 square miles, grew more than sevenfold to 225.40 square miles by 1990.