According to the bar graph, Average production of black tea in 2014,2015 and 2018 ‌‌=‌
100+80+120
3
‌‌=‌
300
3
=100‌ million tonnes. ‌ Average production of green tea in 2016,2017 and 2019 ‌‌=‌
100+130+110
3
‌‌=‌
340
3
=113.33‌ million tonnes. ‌ ∵100<113.33, therefore average production of black tea in 2014,2015 and 2018 is less than average production of green tea in 2016, 2017 and 2019. ∴ Required decrement =113.33−100 =13.33 million tonnes.