Table II.

The percentage of the total number of tests represented by the 10, 20, and 30 most commonly ordered tests.

Year	Total number of ordered tests	10 most commonly ordered tests	20 most commonly ordered tests	30 most commonly ordered tests
2002	3,760,508	40.4%	59.5%	67.6%
2003	3,983,149	47.7%	69.7%	78.7%
2004	4,218,082	47.6%	69.1%	77.6%
2005	4,614,524	48.8%	69.3%	77.1%
2006	5,100,550	48.0%	67.4%	75.8%
2007	5,766,947	47.9%	66.7%	76.2%
2008	6,402,617	47.8%	66.4%	75.7%
Mean	4,835,197	46.9%	66.9%	75.5%