Analysis of the hole reveals that the hole reached its peak size on September 11th, reaching a size of 9.3 million square miles. That's virtually identical to the size it reached in 2013, and certainly smaller than the largest ever recorded size, back in 2000, of 11.5 million square miles. In fact, it's remained a consistent size in 2010, 2012, 2013 and this year.
The ozone layer acts as a protective layer for the planet, shielding us from harmful ultraviolet radiation that can cause skin cancer and damage plants. Research earlier this year suggested that an unexpectedly large amount of ozone-depleting chemical carbon tetrachloride persists in the atmosphere, though—so it certainly pays for NASA to keep a check on it. [NASA]