How accurate are Pollmark's polls?

ELECTIONPollmark POLLACTUAL RESULT
2015-06-07 Genel Seçim
AK Parti: 49.4%
CHP: 23.5%
AK Parti: 40.87%
CHP: 24.96%
2015-11-01 Genel Seçim
AK Parti: 43.9%
CHP: 25.4%
AK Parti: 49.5%
CHP: 25.32%
2011-06-12 Genel Seçim
AK Parti: 47.5%
CHP: 25.2%
AK Parti: 49.83%
CHP: 25.98%