Study the following table, which shows the number of units of a product manufactured and sold by a company in five years, and answer questions.

Years	Number of units (in thousands) Manufactured	sold
2013	350	320
2014	375	315
2015	300	280
2016	450	423
2017	420	360

In which year the number of units of the product sold is 19000 less than the average number of units manufactured per year?