What was the difference in the total number of Laptops and Desktops manufactured in 2009 to the total number of Laptops and Desktops manufactured in 2011?
The difference in the total number of Laptops and Desktops manufactured in 2009 to the total number of Laptops and Desktops manufactured in 2011 = (20500+24700)-(16400+20200)
