Follow CBSMIAMI.COM: Facebook | Twitter

NEW YORK (CBSMiami/AP) — More restrictive laws in some states and the availability of affordable, long-lasting contraceptives are two factors credited with dropping the abortion rate in America to its lowest level since 1974.

READ MORE: Miami Weather: Still A Chill But Milder Afternoon On Tap With Showers Returning

A report released Tuesday by the Guttmacher Institute, a research group which supports abortion rights, said they logged 926,200 abortions in 2014.

The 2014 numbers represent a drop of 12.5 percent from Guttmacher’s previous survey, which tallied 1.06 million abortions in 2011. The decrease was spread nationwide; in only six states did abortions increase over the three-year span.

According to the report, the abortion rate was 14.6 abortions per 1,000 women aged 15-44, the lowest rate since abortion was legalized nationally in 1973 by the Supreme Court’s Roe v. Wade decision.

Following that ruling, the number of abortions in the U.S. rose steadily — reaching a peak of 1.6 million in 1990 — before starting a decline.

Guttmacher’s state-by-state breakdown showed big declines in abortions in some liberal states, such as California, that protect abortion rights, and also in some conservative states, such as Texas, that have passed laws to restrict abortions.

Guttmacher researcher Rachel Jones noted that the majority of women who get abortions have low incomes, and nearly two-thirds are already parents.

READ MORE: Miami Working On Solution As Many Scramble To Find Affordable Rentals

“It can be very difficult for them to arrange for time off from work, transportation and child care,” Jones said. “Some of the abortion rate decline is likely attributable to women who were prevented from accessing needed services.”

The highest abortion rates were in the District of Columbia, New York, New Jersey, Maryland and Florida. The lowest rates were in Wyoming, Mississippi and South Dakota, states that had only one abortion clinic operating in 2014.

According to the report, the number of abortion clinics nationwide declined by 6 percent — from 839 in 2011 to 788 in 2014.

The report’s release comes 10 days before the anti-abortion movement’s annual March for Life in Washington, D.C., and at a time when the movement is emboldened by the outcome of the recent presidential, congressional and state elections.

In Congress, majority Republicans in both chambers are seeking to halt federal funding for Planned Parenthood, which provided more than one-third of the nation’s abortions in 2014, and also to ban most abortions after 20 weeks of pregnancy. President-elect Donald Trump has promised to sign both measures if they reach his desk, and also says he wants to fill a vacancy on the Supreme Court with a “pro-life” justice.

One of Trump’s top advisers, Kellyanne Conway, is scheduled to speak at the March for Life.

At the state level, tough new restrictions on abortion are being pushed in numerous Republican-controlled state legislatures, including Iowa and Kentucky, where the recent election gave the GOP full control. In Kentucky, lawmakers have already moved swiftly to enact a ban on abortions after 20 weeks and to require doctors to perform ultrasounds prior to abortions.

MORE NEWS: Three People Injured In NW Dade Drive-By Shooting

(TM and © Copyright 2017 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo
TM and Copyright 2017 CBS Broadcasting Inc. Used under license. All Rights Reserved. This
material may not be published, broadcast, rewritten, or redistributed. The Associated Press
contributed to this report.)