How accurate are Andy-ar's polls?

ELECTIONAndy-ar POLLACTUAL RESULT
2017-04-16 Anayasa Referandumu
Evet: 53.7%
Hayır: 46.3%
Evet: 51.41%
Hayır: 48.59%
2015-06-07 Genel Seçim
AK Parti: 41.9%
CHP: 25.8%
AK Parti: 40.87%
CHP: 24.96%
2015-11-01 Genel Seçim
AK Parti: 43.7%
CHP: 27.1%
AK Parti: 49.5%
CHP: 25.32%