There are not a whole lot of data points out there. I think that's purposefully done.
One article that I often refer to.... Granted, it's a bit dated, but again, it's a very limited dataset. In 2016, The Wall Street Journal published an article that looked at the 12,800 Syrian refugees who were resettled to the United States under President Obama. They found that less than half of a per cent of those who were resettled were Christians, despite the fact that Christians represented 10% of Syria's pre-war population and despite the fact that genocide had been committed against them. That is a significant under-representation taking place. The reporter did kind of look at the root causes. They did indicate that there were a number of causes for this, but the key cause was placed at the feet of UNHCR—