The visa, which allows American companies to hire highly-skilled foreign workers, is often used by the tech industry. This year, U.S. Citizenship and Immigration Services announced that it received 190,098 applications, marking a noticeable drop from the 199,000 applications in 2017. Applications dropped below 200,000 last year for the first time since 2014, with 2016 representing the peak, when 236,000 applications were received.

Despite the falling numbers, demand for the visa continues to outstrip supply. Only 85,000 H-1B visas are issued for for-profit companies each year—a limit that has not been revised since 2005. Nonprofits, including hospitals and research institutions, are exempt from the cap.

There is no immediately clear cause for the decline. However, the Trump administration and Republican-controlled Congress alike have taken steps to make acquiring the visas more difficult.

Last year, the House Judiciary Committee passed the Protect and Grow American Jobs Act, which seeks to make it more difficult for “H-1B dependent” companies to obtain work permits. And in February, U.S. Citizenship and Immigration Services issued a policy memo outlining a number of additional requirements to verify the nature of the relationship between prospective employers and their employees. The added steps could serve as a deterrent for companies and visa applicants, who may look into other visas that are more easily approved.