How accurate are Mediar's polls?

ELECTIONMediar POLLACTUAL RESULT
2019-03-31 İstanbul Belediye
Yıldırım: 46.12%
İmamoğlu: 43.36%
Yıldırım: 48.61%
İmamoğlu: 48.77%
2018-06-24 Cumhurbaşkanlığı
Erdoğan: 47%
İnce: 29%
Erdoğan: 52.59%
İnce: 30.64%
2018-06-24 Genel Seçim
Cumhur: 46%
Millet: 38%
HDP: 12%
Cumhur: 53.7%
Millet: 33.9%
HDP: 11.7%