The provided line graph illustrates the distribution of average annual expenditure on three phone services: cell phone services, national and international fixed-line services in the US from 2001 to 2010.
Overall, there was a significant increase in the amount of cell phone services. In contrast, national fixed-line services had the highest rate initially, but declined significantly, while international fixed-line services remained stable throughout this period.
In 2001, spending on national fixed-line services was the highest, totaling $700, which was significantly more than the $200 spent on cell phone services and around $250 on international fixed-line services. Subsequently, there was an opposite trend, with a decrease in national fixed-line service spending and an increase in cell phone services. By 2006, the expenditures for both cell phone and national fixed-line services were equal, at $500, while international fixed-line services experienced a slight rise to $300.
From 2006 to 2010, the trends for all three services continued. Cell phone services, which started at the lowest expenditure, ended up with the highest at over $700. Spending on national fixed-line services settled at $400, while international fixed-line services remained constant at $300.