The mobile phone market has experienced significant growth over the past 15 years. In 2001, service revenues exceeded infrastructure costs for mobile networks, and by 2002 service revenues covered 85% of infrastructure costs. This growth was enabled by factors like cell phone towers achieving near complete coverage by 2001 and investments in more efficient network equipment. International growth has also been substantial, with U.S. subscribers growing from 123,000 in 1990 to 45 million in 2005, and Asian subscribers growing even faster from 45,000 to 215 million over the same period. Market analysts predict the growth factors will maintain 10% annual subscriber growth for the next five years.