Global smartphone sales experienced extraordinary growth starting in 2007 with the introduction of both the iPhone and Android-platform based devices (see the Chapter Introduction). Following are the yearly global sales (in million units) for smartphones beginning in 2008 through 2015:

YEAR                       SALES
2008............................140
2009............................173
2010............................305
2011............................495
2012............................730
2013..........................1030
2014..........................1300
2015..........................1430

Develop a linear trend line model to forecast smartphone sales for 2016, 2017, and 2018, and compare these forecasts with those reported on the Internet.