The number of abortions in the US has dropped to the lowest level since the procedure was legalized by the Supreme Court in 1973, according to a new study by the Guttmacher Institute.

The study used data collected by the institute, which defines itself on its website as a “leading research and policy organization committed to advancing sexual and reproductive health and rights in the United States and globally.”

Based on data of abortion incidence and rates between 2014 and 2017, the study found that in 2017, 862,320 abortions were conducted in clinical settings across the US. That represents a 7% decrease in abortions since 2014.

The US abortion rate in 2017 - 13.5 abortions per 1,000 women aged between 14 and 44 - was also the lowest it’s been since the procedure’s legalization.

Abortion rates were highest in the District of Columbia, New Jersey, Maryland, Florida, and New York in 2017 and lowest in Wyoming, South Dakota, Kentucky, Missouri and Idaho.

The report also found that there was a 2% increase in the number of clinical facilities that carry out abortions in 2017 compared to 2014. However, there were regional and state disparities in the facilities’ distribution. While the number of clinics in the Northeast and West increased by 16% and 4%, respectively, the number in the Midwest and South decreased by 6% and 9%, respectively.

Even though the number of abortions in the US is on the decline, the period of 2014 to 2017 saw around a 25% increase in medication abortions, which, unlike surgical abortions, use pills to induce the abortion.

The report also states that there are multiple factors contributing to the declining abortion rate in the US, including “improvements in contraceptive use and increases in the number of individuals relying on self-managed abortions outside of a clinical setting.”

In fact, the report found that 18% of nonhospital medical facilities in 2017 said they had seen “one or more patients for a missed or failed abortion due to self-induction,” compared to only 12% in 2014.

“Reports of self-managed abortion were highest in the South (25%) and the West (21%), compared with 10% in the Midwest and 14% in the Northeast,” the report adds.