Statistical summary

Centralized Control and Majoritarian System: 12/44 = 27%
Centralized Control and Proportional System: 2/44 = 4.5%
Centralized Control and Mixed System: 3/44 = 6.8%
Centralized Control and Majoritarian and Nomination System: 13/44 = 29.5%
Centralized Control and Proportional and Nomination System: 5/44 = 11%
Centralized Control and Majoritarian, Proportional, and Nomination System: 2/44 = 4.5%
Centralized Control and Nomination System: 7/44 = 16%
Centralized Control and Without an Upper House: 61/105 = 58%