I've posted on the H-1B subject many times.
The “65,000” number is utterly bogus, but is published everywhere.
The minimum estimate for H-1Bs in 2015 is 550,000.
One researcher at CIS (the site you link, and the best site for hard data on this) recently estimated just short of 1 million H-1Bs.
Here's a quick - and current - summary for those who are interested:
(1) 65,000 is the yearly quota for tech workers with B.S. degrees. Add in 20,000 more per year for those with M.S. and PhDs.
(2) Now multiply times six! Why? Because each visa is automatically renewable for six years! So, that's 510,000 right there.
(3) After six years, H-1Bs with active applications for Green Cards may renew 1 year at a time - indefinitely.
(4) H-1Bs employed by universities, government agencies, and non-profit laboratories do not count against the quota. No one has any idea how many there are.
(5) There are at least 100,000 more foreign workers in the USA who are legally using various kinds of student, training, internship, and travel visas to work full time jobs here.
Don’t forget to start adding in H4s (Spouse work permits) for all these H1BS. And a newer program...I think called OPT. From student to H1b. There seems to be 21 different types of temporary work visas. Add all those in. Plus asylees, refugees, overstays. People cant begin to grasp #s or complexity of immigration law.