Missing Countries & Territories

Asia：

Yemen

North America：

Dominica

Africa: 

Central African Republic
Equatorial Guinea
Guinea-Bissau
Somalia
Western Sahara

Oceania: 
Marshall Islands

Territories:

British Indian Ocean Territory (UK)

Saint Helena (UK) 

Ascension (UK)
American Samoa (USA)
Guam (USA)
U.S. Minor Outlying Islands (USA)
Saint Eustatius (Netherlands)

Saba (Netherlands)
Tokelau (New Zealand)