Computational domain coverage of the protein sequence space from 2009 to 2011. From April 2009 to December 2011, the NR database grew twice: from 2.8 to 5.6 billion aa. Three Pfam releases represent both model improvements and an increase in the number of domain models (shown in parentheses).
Rekapalli et al. BMC Genomics 2012 13:634 doi:10.1186/1471-2164-13-634