6band
The graph below shows US consumers' average annual expenditures on cell phone and residential phone services between 2001 and 2010. Increasing usage of cell phones over residential phones has shown a great shift in their services over time. Looking at the data in the graph we can see the cell phone services from the period of 2001 to 2010 have multiplied 4 times in a decade conversely the residential phone services have shown a ...