The figure below depicts natural fluctuation of ozone levels in Switzerland between 1925 and 1976. Dobson units are a way to measure the total amount of atmospheric ozone above a point on the Earth's surface.
What can you conclude from this figure?

Question

The figure below depicts natural fluctuation of ozone levels in Switzerland between 1925 and 1976. Dobson units are a way to measure the total amount of atmospheric ozone above a point on the Earth's surface. 
What can you conclude from this figure?

Quizplus · Accepted Answer

The figure shows that ozone levels fluctuate year to year and do not follow a distinct pattern. The average for the 50-year span appears to be around 330 Dobson units, as this is the value to which the line generally seems to oscillate around. However, there are periods where the value is higher or lower than this. The figure does not provide information about whether Switzerland is a model example or whether all small European countries will show fluctuations in ozone concentration levels.

The Figure Below Depicts Natural Fluctuation of Ozone Levels in Switzerland