The U.S. travel ban including five Muslim majority countries has majorly reduced new U.S. residents from the places affected. New residents from Yemen were a lot fewer – their numbers were reduced by 87 percent in two years. While in FY 2016, almost 13,000 Yemenis took up residence in the United States, that number was slashed to 1,600 in FY 2018. The number of new residents from Iran was reduced by 44 percent in the same time frame.
The National Foundation for American Policy, which analyzed DHS data for their report, excluded refugees and asylees from the count since they are often in the United States years before officially taking up residence because of slow asylum proceedings and a considerable backlog.
The travel ban, also referred to as the Muslim ban, is officially called Executive Order 13780. It was implemented in March 2017 as one of the first official acts carried out by newly inaugurated President Donald Trump (together with Executive Order 13769 of similar content which preceded it in January). As part of the order, certain visa categories ceased to be available for nationals of Iran, Libya, Yemen, Somalia and Venezuela. In the case of Syria and North Korea, the entry of all nationals was suspended.