The changes in corn harvests (in billions of bushels) in the United States from one year to the next are shown in Table 24.
Table 24
Changes in Corn Harvests
Change in Corn Harvest
Years (billions of bushels)
2008–2009 ……………………… 1.0
2009–2010 ……………………… -0.6
2010–2011 ……………………… -0.1
2011–2012 ……………………… -1.6
2012–2013 ……………………… 3.1
2013–2014 ……………………… 0.3
a. If 12.1 billion bushels of corn were harvested in 2008, what was the amount of corn harvested in 2014?
b. During which period(s) were corn harvests increasing?
c. During which period(s) were corn harvests decreasing?