From the report that is the basis of that study:
https://www.dhs.gov/sites/default/fi...20Re port.pdf
"An overstay is a nonimmigrant who was lawfully admitted to the United States for an authorized period but stayed in the United States beyond his or her lawful admission period. "
So the report is about people entering the states for all purposes like tourist, students, etc. NOT IMMIGRANTS.
"It is important to note that the total number of FY 2015 overstays, as identified in this
report, does not equal the total number of FY 2015 overstays that currently remain in the United States. That number is likely lower. This is because foreign nationals identified as possible overstays can and do subsequently depart the United States, or have been
found to have adjusted their lawful status. For purposes of this report, these are still considered overstays."
According to this report, the suspected overstay rates for 2015 for the seven banned countries are with suspected in country overstay numbers:
Iraq -6% - 681 people
Iran - 2% - 564 people
Libya - 4.5% - 56 people
Somalia - 1.4% - 2 people
Sudan - 7.5% - 278 people
Syria - 3% - 440 people
Yemen - 6% - 219 people
total people suspected to be overstaying their visa inside the US: 2,240
Total people from ALL countries EXCEPT Mexico and Canada expected to be overstaying their visa inside the US: 210,825
So all of this is to stop .01% of people from overstaying their visas? Why was a global ban with a huge press release etc needed when continuing the screening as per Obama's policy would have done just fine?