The graph illustrates the number of cases of X disease in Someland between 1960 and 1995. In general, there was a significant growth of cases from 1965 to 1980. However, the disease reduced sharply after 1980 and then disappeared by the year 1990.
In 1960, there were approximately 100 cases of the disease. This number remained steadily until 1970, after that, the incidence increased gradually and reached its maximum level in 1975, which was recorded to be 500. The figure stayed stable for 5 years.
After 1980, the number of cases started to decrease significantly, from 500 to around 350 cases. In 1990, the number reduced sharply to zero. Over the year, the figure of cases remained constant and did not show any further rise.
