A new report from the Centers for Disease Control and Prevention (CDC) shows that abortion rates are down across the board and suggests that people are able to more effectively plan their reproductive futures. Yet, the Trump administration has finalized a regressive set of health insurance policy changes that could roll back access to the very thing that has helped us get here: birth control.

For the report, the CDC looked at data from central health agencies in the District of Columbia, New York City, and 47 states (excluding California, Maryland, and New Hampshire) for every year from 2006 to 2015, and found a steep decline using every metric. In fact, all three metrics—the total number, rate, and ratio of abortions (the amount of abortions there are compared to live births)—reached historic lows for the study period (2006–2015).

The total number of reported abortions decreased 24 percent during this period, from 842,855 in 2006 to 638,169 in 2015. The rate of abortions among women ages 15 to 44 fell 26 percent, from 15.9 abortions per 1,000 women to 11.8. And the abortion ratio decreased as well, by 19 percent.

The report found that these numbers declined across all age groups, races, and ethnicities, yet “well-documented disparities persist.” For instance, abortion rates are 1.5 times higher among Hispanic women than among non-Hispanic white women, and 3.6 times higher among non-Hispanic black women than among non-Hispanic white women.

But the major factor behind these downward trends isn't our shrinking access to abortions (although that undoubtedly played a role)—it's our increased access to birth control. "Efforts to help women avoid pregnancies that they do not desire might reduce the number of abortions,” the report reads, continuing on to say that "providing contraception for women at no cost can increase use of these methods and reduce abortion rates.”

The CDC report follows previous research that showed that access to effective birth control could lead to lower abortion rates, likely by helping to prevent unintended pregnancies.

For instance, research from the Guttmacher Institute looking at data from 2008 to 2011 found that “the steep drop in unintended pregnancy—including births and abortions—was likely driven by improved contraceptive use.”

The researchers point specifically to increased use of highly effective long-acting reversible contraceptives (LARCs)—such as IUDs and implants—during this period. These forms of birth control "don’t have much room for user error, and so people are less likely to accidentally get pregnant,” Rachel Jones, Ph.D., principal research scientist at the Guttmacher Institute, tells SELF.

Later, the implementation of the Affordable Care Act (ACA) in 2012 bolstered this trend with its birth control mandate, which requires employers to offer insurance plans that cover at least one form of FDA-approved birth control from each method category at zero cost to the patient (meaning no co-pay or co-insurance). (The mandate included exemptions for churches and certain religious organizations, like Catholic hospitals.)

These provisions "appear to have spurred continued improvements in contraceptive use beyond 2012," according to Guttmacher. The mandate made it more economically feasible for women to afford contraceptives, and previously cost-prohibitive LARCs in particular, Jones says. A study of 417,221 women in Contraception found that between 2012 and 2014, the rate of women paying out of pocket for an IUD fell from 58 percent to 13 percent. And research shows that when financial barriers are removed, women are much more likely to choose LARC methods, and therefore less likely to experience an unintended pregnancy and subsequent abortion.