The graph below compares the average amount of money spent on cell phone and residential phone services per year over the period of the first decade of the 21st century.
It is clear that there is a reverse relation between the increase of expenditure on cell phones compared to the residential phone services.
In 2001, the money spent on cell phone services was minimal before the beginning of its revolution. In contrast, the residential phone services expenditures were reaching its peak before starting to fail.
As we see between the years 2005-2006, the situation changed, and cell phone services exceeded the residential phone services in expenditures. Moreover, in 2010, the cell phone service was by far the most money spent compared to residential phone services. Throughout the whole period, cell phone service was rising constantly, while residential phone services were constantly decreasing, when talking about the money spent on each of them