The given line graphs illustrate the changes in the ozone hole size over the Antarctica region and the amounts of three gases produced that caused damage to the ozone layer from 1980 to 2000.
The ozone hole was at its smallest size of about 400 thousand square kilometers in 1980, but 20 years later, it grew drastically to 3.6 million square kilometers. It increased ninefold. The only period when there was a reduction in size was in the early 1990s (from 2 to 1.2 million square kilometers).
In 1980, about 70 million tonnes of CFC–11 were produced, which remained stable for 3 years before undergoing a steady decline to below 10 million tonnes in the late 1990s. The production of CFC–12, on the other hand, showed an upward trend throughout the 20-year period from 25 to 50 million tonnes, surpassing the production of CFC–11 in 1989. N2O, however, was not produced until 1990, but its production grew rapidly to about 40 million tonnes by the year 2000.
Overall, the two graphs indicate that it was mainly CFC–12 and N2O that gave rise to the expansion of the ozone hole over Antarctica in the last two decades of the 20th century.