The given line graph reveals the X disease incidence in Someland over a period of 35 years ending in 1995. In general, this figure followed a downward trend throughout the latter half of the featured time frame.
As can be seen clearly from the graph, standing at approximately 100 in 1960, this figure increased steadily to 200 in the year 1970, and then the disease began to spread rapidly in the following years, with the number of patients roughly 500 in 1975. The number of cases remained roughly stable at 500 cases for the next five years.
In the next 10 years, there was a sharp decrease in the number of cases, and no reported cases were recognized by 1990. In the following 5-year period, the number of people suffering from X disease remained constant at zero, which was dramatically lower than the starting point. By the time, Someland was free from the illness.