Refer the below data table and answer the following Question.

	2011	2012	2013	2014	2015
Company A	3000	3000	1000	2000	2000
Company B	5000	4000	2000	3000	4000
Company C	3000	5000	3000	4000	5000

For which of the following pairs of years the total exports from the three companies together are equal?

(Note: Figures given are in lakh rupees)