The line graph below displays the prevalence of X disease in Someland between the years 1960 and 1995.
Overall, from 1960 to 1980 saw a significant rise in the cases of X disease and hit the highest number in the examined years. Otherwise, in the following years, the number was gradually decreased after 1980 and reached the lowest level until the end of the period.
In the first five years, there was a slight increase in the number of cases of disease X, which was stood at about 100 cases. In 1970, the amount of the patients suffering from this disease continued to increase and has doubled previous year’s number and accounted for 200 cases. The number of the patients rose significantly and hit the peak in 1975, which totaled 500 cases and stayed unchanged for the next five years.
On the other hand, 1980 to 1985 saw a fluctuation in the spreading of the disease, which was followed by a sudden decrease and accounted for 350 cases. However, over the following five years, there was a sharp fall to zero cases. At the end of the period, as can be seen, no patients with this disease were found in Someland and it can be said that disease X had disappeared.