Here is data on per capita consumption (in pounds) of mozzarella cheese in the US and the number of Ph.Ds in civil engineering awarded in the US for the years 2000 - 2009.
Year Mozzarella Ph.Ds
2000 9.3 480
2001 9.7 501
2002 9.7 540
2003 9.9 552
2004 10.2 547
2005 10.5 622
2006 11 655
2007 10.6 701
2008 10.6 712
2009 10.6 708
Corrrelation = .95865
Explain why there is such a strong positive correlation in this case?