After forming partnerships with multinational corporations such as Sprint, ITT and Telenor, these firms now offer the cheapest and clearest phone calls in Africa. These Somali telecommunication companies also provide services to every city, town and hamlet in Somalia. There are presently around 25 mainlines per 1,000 persons, and the local availability of telephone lines (tele-density) is higher than in neighboring countries; three times greater than in adjacent Ethiopia. Prominent Somali telecommunications companies include Somtel Network, Golis Telecom Group, Hormuud Telecom, Somafone, Nationlink, Netco, Telcom and Somali Telecom Group. Hormuud Telecom alone grosses about $40 million a year. Despite their rivalry, several of these companies signed an interconnectivity deal in 2005 that allows them to set prices, maintain and expand their networks, and ensure that competition does not get out of control.
what is another word for availability of telephone lines? (If the question is unanswerable, say "unanswerable")
tele-density