We pick k.root-servers.net, one of the 13 root servers (1), and ask it about www.ulum99.xtgem.com and learn that com is delegated to 13 name servers (2), so we ask j.gtld-servers.net where we learn that xtgem.com is delegated to two name servers, including ns2.xtgem.com (3), so we ask that one and get the following answer:
Six percent of them use the name server ns1.xtgem.com.
The IP number 188.95.50.114 only
Six percent of the several thousand of host names that point only to the IP number 188.95.50.114 use the two name servers ns1 and ns2.xtgem.com together.