Since there is no ozone hole at either pole about half the year, the answer is "Zero". Beyond this, we have only ~20 years worth of data, new and improved methods of determining the size of the hole, and shifting definitions of what is an "ozone hole". But for the most part, the smallest holes were the oldest recorded ones.
The Largest hole in the ozone is currently over the Antarctic. However it is getting smaller, and is the smallest it has ever been for a decade.
The ozone layer is the result of a continuous process of both making and destroyinig ozone. Sometimes there is more, sometimes there is less. The largest the ozone hole ever was recorded was a reduction in total global ozone of about 10%, and the hole is (so far) getting smaller.
NIMBUS-7
Ozone can spread. Ozone replenishment is a natural process.
The name of the hole is ozone hole. It is the thinning of ozone layer.
The ozone depletion is not a natural process. If the man made processes depleting the ozone are stopped then there will be no depletion of ozone to cause an ozone hole.
a hole in the ozone layer.
The hole in ozone is not actually a hole. It is just the thinning of ozone layer.
Ozone hole is the thinning of ozone layer. It is due to ODS.
A hole in ozone layer means that the concentration of ozone molecules have fallen below a certain level. Ozone hole is commonly misunderstood as a hole in the ozone layer.
Newspapers reports give a full insight into what is happening in ozone. The ozone hole is a hole in ozone layer.
The ozone hole is not actually a hole in the ozone layer. It is actually the thinning of ozone layer below a certain concentration.