Context: CREATE TABLE table_name_21 (density__hab__km²__ VARCHAR, population_under_1_year_old_censo_2007_hab_ VARCHAR)
Question: What is the density (hab/km²) with a population under 1 year-old censo 2007(hab) of * data from the census taken by the Inei?
Answer: SELECT density__hab__km²__ FROM table_name_21 WHERE population_under_1_year_old_censo_2007_hab_ = "* data from the census taken by the inei"