Table 5.

Threshold levels used to define the experimental quality classes on the all PDB set.

	Medium	High	Very High
Resolution	<= 2.5	<= 2.2	<= 1.7
R-free	<= 0.3	<= 0.25	<= 0.22
Relative frequency	76.7%	42.2%	8.7%
# Cases	10,771	5,926	1,222