Scoring: São Tomé and Príncipe

• Date of joining: 1975-09-16
• Expected count from Wikipedia (Miguel Trovoada onwards): 21
• Number in Wikidata: 9
• PositionHolderHistory warnings: 7
• Score: 76/210 = 36%

It’s possible that the expected figure should be higher, to reflect the 1979–88 period during which the position of Prime Minister was abolished.