United States: In 2003, from data collected in those areas that sufficiently reported gestational age, it was found that 6.2% of abortions were conducted between 13 and 15 weeks, 4.2% between 16 and 20 weeks, and 1.4% at or after 21 weeks. [18] Because the Centers for Disease Control and Prevention's annual study on abortion statistics does not calculate the exact gestational age for abortions performed past the 20th week, there are no precise data for the number of abortions performed after viability. [18] In 1997, the Guttmacher Institute estimated the number of abortions in the U.S. past 24 weeks to be 0.08%, or approximately 1,032 per year. [19]