The graph below shows changes in global food and oil prices between 2000 and 2011.
The line graph compares the average price of a barrel of oil with the food price index over a period of 11 years.
It is clear that average global prices of both oil and food rose considerably between 2000 and 2011. Furthermore, the trends for both commodities were very similar, and so a strong correlation 93.6% is suggested.
In the year 2000, the average global oil price was close to $25 per barrel, and the food price index stood at just under 90 points. Over the following four years both prices remained relatively stable, before rising steadily between 2004 and 2007. By 2007, the average oil price had more than doubled, to nearly $60 per barrel, and food prices had risen by around 50 points.
A dramatic increase in both commodity prices was seen from 2007 to 2008, with oil prices reaching a peak of approximately $130 per barrel and the food price index rising to 220 points. However, by the beginning of 2009 the price of oil had dropped by roughly $90, and the food price index was down by about 80 points. Finally, in 2011, the average oil price rose once again, to nearly $100 per barrel, while the food price index reached its peak, at almost 240 points.
The line graph shows the average annual expenditures on cell phone and residential phone services between 2001 and 2010.
The line graph compares average yearly spending by Americans on mobile and landline phone services from 2001 to 2010.
It is clear that spending on landline phones fell steadily over the 10-year period, while mobile phone expenditure rose quickly. The year 2006 marks the point at which expenditure on mobile services overtook that for residential phone services.
In 2001, US consumers spent an average of nearly $700 on residential phone services, compared to only around $200 on cell phone services. Over the following five years, average yearly spending on landlines dropped by nearly $200. By contrast, expenditure on mobiles rose by approximately $300.
In the year 2006, the average American paid out the same amount of money on both types of phone service, spending just over $500 on each. By 2010, expenditure on mobile phones had reached around $750, while the figure for spending on residential services had fallen to just over half this amount.