Knowledge of the observed data as well as the theoretical mechanisms is important to the better understanding of man's impact on stratospheric ozone. For example, the results of mechanistically modeling the chlorofluoromethane effects on ozone suggest that the largest predicted percent depletion will occur at 40 to 45 km altitude. The search for unusual or abnormal changes in ozone can be enhanced by the use of quantitative statistical analysis of the data. This can improve the separation of the real from the random effects. Trend detection followed by identification of cause, not only provides a direct comparison with theory but also can be used as an early warning indicator if made sensitive enough. Trend detection is therefore an important technique in better understanding man's role in affecting stratospheric ozone. The mean total ozone levels increase as the distance from the equator increases with some reversal near the poles. The amplitude of the annual cycle also exhibits a similar latitudinal dependency.