Total production for two years together by unit F is what % of the total production of the two years together by unit D? (rounded off to two digits after decimal)

As we can see in the graph that
Total production by unit F in year 2001 and 2002 together = ( 70 + 85 ) = 155 Million tons
Similarly
Total production by unit D in year 2001 and 2002 together = ( 95 + 100 ) = 195 Million tons
∴ Required percentage = (Total production by unit F in year 2001 and 2002 together x 100 / Total production by unit D in year 2001 and 2002 together )
∴ Required percentage = ( 155 x 100 / 195 )
=79.487 ≈ 79.49