The greater region covers approximately 2,000,000 kmÂ and is inhabited by about 94.2 million people ( Ethiopia : 79 million , Somalia : 10 million , Eritrea : 4.5 million , and Djibouti : 0.7 million ) . It covers approximately 2,000,000 kmÂ ( 772,200 sq mi ) and is inhabited by about roughly 100 million people ( Ethiopia : 85 million , Somalia : 9.3 million , Eritrea : 5.2 million , and Djibouti : 0.86 million ) .