BLOOMINGTON — Indiana’s rate of population growth has fallen for a sixth straight year.

The Indiana Business Research Center at Indiana University in Bloomington said Thursday that U.S. Census Bureau estimates show Indiana’s population grew by just 0.32 percent in 2012, but that was still higher than those of each of its adjacent states. Researchers say sluggish population growth has been the norm in many parts of the country.

Researchers say several central Indiana counties remain among the fastest growing in the state, but even their rate of growth is falling off. While Hamilton County north of Indianapolis remained the state’s fastest-growing county with a 2.2 percent increase last year, that rate falls short of its annual growth rate from 2000 to 2010.