All the quizzes in this series are from https://worldpopulationreview.com/. All of the populations are of the city proper. My series is complete. The countries that have less than 15 cities and that are not in this series are: Andorra, Antigua & Barbuda, Bahrain, Barbados, Belize, Brunei, Djibouti, Dominica, Equatorial Guinea, Eritrea, Fiji, Micronesia, Grenada, Guinea Bissau, Guyana, Iceland, Kiribati, Lesotho, Liechtenstein, Marshall Islands, Mauritania, Monaco, Nauru, Qatar, Rwanda ect.