By Byron York

NEA Columnist

Among the many criticisms of Donald Trump's ban-Muslim-immigration proposal is that it is based on bogus data. In his statement announcing the proposal, Trump cited a survey from the conservative Center for Security Policy showing that "25 percent of (Muslims) polled agreed that violence against Americans here in the United States is justified as a part of the global jihad" and also that 51 percent "agreed that Muslims in America should have the choice of being governed according to sharia."

Critics attacked the Center for Security Policy poll as unreliable. "Donald Trump's call to ban Muslim immigrants is based on a very shoddy poll," read a Washington Post headline, reflecting a widely held view.

So throw out that particular poll. Is there some other data, from sources with agreed-upon credibility, to shed light on Trump's point, or whether he has a point at all? Recently the Pew Research Center, which has conducted surveys on Muslims in the United States and around the world over the last several years, repackaged some of its findings to help people understand the issue.

A few basic points. According to Pew, Muslims make up 0.9 percent of the U.S. population -- about 2.75 million people. That share is expected to increase to 2.1 percent by 2050. At the moment, 63 percent of Muslims in the United States are immigrants.

The pace of Muslim immigration to the U.S. has picked up significantly in recent years. "A recent Pew Research Center report estimated that the Muslim share of immigrants granted permanent residency status (green cards) increased from about 5 percent in 1992 to roughly 10 percent in 2012, representing about 100,000 immigrants in that year," Pew reports.

As far as beliefs and attitudes are concerned, Pew asked Muslims in 39 countries whether they want sharia to be law of the land where they live. The percentage who answer yes is very, very high in some countries: 99 percent say yes in Afghanistan, 91 percent in Iraq, 84 percent in Pakistan. On the low end, just 12 percent of Muslims in Turkey say they want sharia to be the law of the land; the number is 10 percent in Kazakhstan.

The United States admits a lot of immigrants from the countries whose Muslim populations favor sharia. According to a separate report from the Senate Immigration Subcommittee, the U.S. awarded 11,000 green cards to immigrants from Afghanistan from 2009 to 2013, 83,000 to Iraqis in the same time period, and 83,000 to Pakistanis. The U.S. awarded 22,000 green cards to Turks in that time, and 7,000 to Khazaks.

On the question of violence, Pew asked Muslims around the world the following question: "Some people think that suicide bombing and other forms of violence against civilian targets are justified in order to defend Islam from its enemies. Other people believe that, no matter what the reason, this kind of violence is never justified. Do you personally feel that this kind of violence is often justified to defend Islam, sometimes justified, rarely justified, or never justified?"

"Muslims mostly say that suicide bombings and other forms of violence against civilians in the name of Islam are rarely or never justified, including 92 percent in Indonesia and 91 percent in Iraq," Pew reported. On the other hand, in some countries, the "justified" answers are quite high. In Afghanistan, for instance, 18 percent say such violence is often justified; 21 percent say sometimes justified; 18 percent say rarely justified; and 40 percent say never justified. Four percent say they don't know.

In the United States, Pew found that 81 percent of U.S. Muslims say such violence is never justified; five percent say it is rarely justified; seven percent say it is sometimes justified, and one percent say it is often justified. Six percent say they don't know.

Read the numbers however you like. Some observers stress that large majorities of Muslims in the United States and in some other countries oppose such violence under all circumstances. Others point to those Muslims in the United States who believe it is justified in at least some cases -- 13 percent -- and say that is an unacceptably high number. And of course, Trump's proposal targets Muslims from other places in the world coming to the United States, which involves some Muslim-majority countries in which approval of violence in the name of Islam is alarmingly high. It's a complicated story, but at least there are some reliable numbers on which to base the debate.