All statistics measuring abortion in the U.S. — the rate, the ratio to live births, and the absolute number — reached a "historic low" in 2016, according to new data released Wednesday from the Centers for Disease Control and Prevention.

In 2016, the most recent year available, the government agency reported 623,471 abortions, the lowest number the CDC has ever seen since it began tracking the procedure in 1969, according to the study. That's a 2.3% decline from 2015, when the CDC recorded 638,169 instances of the procedure.

During the same time period, the abortion rate dropped to 11.6 abortions per 1,000 women of reproductive age and the ratio fell to 186 abortions per 1,000 live births, according to the CDC's data. The agency compiled data from 48 reporting areas — 47 states plus New York City. (California, Washington D.C., Maryland and New Hampshire did not report data.)

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The government agency's data were similar to results released earlier this year from the Guttmacher Institute, a research organization that supports abortion rights. According to Guttmacher, the abortion rate was 13.5 abortions per 1,000 women aged 15 to 44 in 2017, the lowest rate recorded since Roe v. Wade, the 1973 Supreme Court decision that legalized abortion nationwide. That's an 8% decline from 2014, the last time Guttmacher calculated the United States' abortion rate, and 54% lower than when the group recorded the peak rate in 1980.

Guttmacher attributed the decline to two factors: a declining pregnancy rate and a growing disparity between abortion access in liberal and conservative states. That divide stems largely from laws targeting the operations of clinics that provide abortions, a style of regulation known as a Targeted Regulation of Abortion Provider, or TRAP, law.

With a newly conservative Supreme Court, access to abortion has come under fire across the South and Midwest, where state lawmakers have raced to pass laws that ban the procedure in hopes of overturning Roe v. Wade.

In 2019, state politicians have introduced 300 bills restricting access to abortion, according to data compiled by the Guttmacher Institute. Twelve states have passed abortion bans, none of which are currently in effect.

In Wednesday's CDC study, the agency reported that 59% of people who received an abortion in 2016 already had at least one child. Additionally, the CDC reported just under two-thirds of abortions in 2016 occurred at or before eight weeks into a pregnancy, and 91% of all abortions happened at or before 13 weeks into a pregnancy. Nearly 28% of the 2016 abortions involved use of medication, rather than surgery.