Complex sentence: In the 1990 U.S. Census, 1,549 people identified themselves as Abenaki and in the 2000 U.S census it rose to 2,544 with 6,012 people claiming Abenaki heritage.
Split into simpler sentences: In the 1990 U.S. Census, 1,549 people identified themselves as Abenaki. So did 2,544 people in the 2000 U.S census, with 6,012 people claiming Abenaki heritage.