CTIA’s Semi-annual wireless industry survey shows that the estimated US wireless subscriber base grew by 13.7% to over 180 million in 2004. This translates to over 60% of Americans! Not only did the user base grow but over a trillion wireless minutes were used in 2004 (up significantly from 2003’s about 800 billion minutes)
The CTIA report can be purchased for the member price of $850 USD or non-member price of $1,075 USD (ouch! and ouch! again). The ‘More information’ link gives you access to some charts that describe the growth since 1985 as well as other statistics such as Cumulative Capital Investment, Wireless Minutes of Use and more.