Table 1.

Characteristics of the study population

Year	2009	2010	2011	2012
Population (n)	64 637 752	63 962 071	64 988 016	65 792 296
Proportion of Women (%)	53.5	53.4	53.3	53.2
Total number of psoriasis patients (n)	1 419 537	1 440 807	1 477 333	1 512 769
Total number of psoriatic arthritis patients (n)	127 334	137 763	146 463	156 182

Data collected for the morbidity-based risk adjustment of the statutory health insurance companies in Germany from 2009 to 2012.