MODEL ANSWER:

The number of flight diversions with its reasons in four major airports in the USA in 1990 and 2000 is tabulated in the given charts.

As per the table, most diversions were reported in Chicago and the prime cause for this was overhead congestion. Out of the 1397 diversions in Chicago in both the years, just 323 were attributed to bad weather and other reasons. It is also noted that there was an increase in diversions (384 from 345 in 1990) between the years due to this cause. The number of diversions in other cities (New York, Texas and Washington) owing to overhead congestion ranged between 60 and 233 in the former year, whereas it became higher in the latter year. In case of aggregate diversions due to bad weather, Texas stood first (130). However, the disparity of diversions between the years was the highest in New York.(64 from just 12 in 1990). It is also noted that flight diversions due to other reasons was the highest in Chicago in both the years (98 and 102 respectively), however, it had the least increase in such incidents (4).

Overall, it is clear that irrespective of reasons, there was an increase in the number of flight diversions in all four US airports between the years.