The two line graphs illustrate how the ozone hole size change over the Antarctica region and the amount of three different gases produced altogether which caused damage to the ozone layer during the same period between 1980 and 2000.
At first, the ozone hole was it smallest size of about half of thousand square kilometers in 1980, but two decades later, it was enlarged by 9 times to 3.6 square kilometers. The only period when there was a reduction in size was in the early 1990s, from 2 to 1.2 million square kilometers.
Turning to the second graph, CFC-11 was initially released the highest amount of damaging gas to ozone layer and remained stable for two years before undergoing a steady decline to below 10 millions in the late 1990s. The production of CFC-12, on the other hand, showed an upward trend throughout the 20-year period from a third to half of hundred millions tonnes, surpassing the production of the former in 1989. Despite the latest emerging, N20, on the contrary, its production grew rapidly to roughly 40 millions tonnes in 2000.
Overall, the two graphs demonstrate that it was mainly CFC-12 and N20 which gave rise to the expansion of the ozone hole over Antarctica in the last two decades of the 20th century.
