The TSA employs twice as many employees as the private comapnies did. Each lane has at least one, most times two more screeners than pre-9/11.

As for loads, that is a misleading statistic. Loads may be up, but there are far fewer available seats.

80% of 100 = 80
75% of 200 = 150

There are still far fewer people flying today than in 2000.