Those numbers are skewed because they count visa extensions and transfers to a different company instead of just new H1Bs arriving. They also don't count people

Those numbers are skewed because they count visa extensions and transfers to a different company instead of just new H1Bs arriving. They also don't count people leaving, except in the sense that they won't apply for an extension or transfer in 3 years. The country numbers are also skewed because someone from countries other than India/China, say France, shows only once or twice in your data before they get their green card and don't have to renew their work visa. This is because of the hard cap of 7% per country for work green cards regardless of the size of the country. i.e countries with a billion plus people have the same 7% limit as tiny countries.