number_amendments_(democracy)
age_constitution_(democracy)
log_age_constitution_(democracy)
gdp_cap_ppp_(2011$)_2006
gdp_cap_ppp_(2011$)_2007
gdp_cap_ppp_(2011$)_2008
gdp_cap_ppp_(2011$)_2009
gdp_cap_ppp_(2011$)_2010
gdp_cap_ppp_(2011$)_2011
gdp_cap_ppp_(2011$)
log_gdp_cap_ppp_(2011$)