And that's using his own artificial terminus a quo of 1975. Why not pick 1978, or 1992?!
In America we've gone to enormous expense to protect children in car seats and adults with seat belts and air bags, but the libertarians think that preventing your death at the hands of a Muslim head-cutter is an impediment to economic growth.
Cato's Iranian American Alex Nowrasteh, here:
Foreign-born terrorism on U.S. soil is a low-probability event that imposes high costs on its victims despite relatively small risks and low costs on Americans as a whole. From 1975 through 2015, the average chance of dying in an attack by a foreign-born terrorist on U.S. soil was 1 in 3,609,709 a year. For 30 of those 41 years, no Americans were killed on U.S. soil in terrorist attacks caused by foreigners or immigrants. Foreign-born terrorism is a hazard to American life, liberty, and private property, but it is manageable given the huge economic benefits of immigration and the small costs of terrorism. The United States government should continue to devote resources to screening immigrants and foreigners for terrorism or other threats, but large policy changes like an immigration or tourist moratorium would impose far greater costs than benefits.