Teenagers are using long-lasting methods of contraception more than ever, according to a new report published by the Centers for Disease Control and Prevention. It may be one of the reasons why the birthrate among teenagers has been declining over the past 30 years.

Over 19% of girls aged 15 to 19 years old have used IUDs or implants between 2015 and 2019. That’s three times more than in 2011 to 2015. These long-term methods of contraception offer years of protection and are more effective than other options like condoms and the pill, although they require frequent access to a health care provider.

“Public health focuses on these because they’re easy to use,” Joyce Amba, a social scientist at the CDC’s National Center for Health Statistics and co-author of the report, told TIME. “They don’t require a daily regimen like a pill, and they’re very effective.”

Teenagers appear to be more knowledgeable about their options when it comes to birth control. The report indicates they are increasingly using more than one method of contraception. Teenagers are also using more varied forms, such as emergency contraceptives, which were used by 22% of girls from 2015 to 2019 as opposed to 8% from 2011 to 2015.

Access to birth control and reproductive rights have recently been at the forefront of political discourse. Since the U.S. Supreme Court overturned the federal right to abortion last year, women and girls have been increasingly seeking long-lasting methods of contraception, according to TIME.

“The data in the future will be very interesting,” Amba told the news outlet, adding that it is too early to know where these trends are heading.