The provided line graph demonstrates data on the number of incidences of X disease which were reported in Someland over the course 35 years from 1960.
As seen in the graph, although the rates demonstrated an upward trend in the first half of the period, the incidences decreased and vanished in the second half.
To begin with, the number of cases of X disease in Someland stood at a little below 100 at the beginning of the period. In the next half of the decade, the number of incidents slightly went upwards to around 100 cases. The incidences doubled in 1970 compared to that in previous period. The number of cases increased radically until 1975, when it reached a peak at 500 incidences. However, between 1975 and 1980, the number of cases remained stable. On the other hand, in the following five years, the number of cases decreased moderately to well above 300. There was a considerable fall in the number of cases before dipping in 1990. During the final years, no incidents were reported in Someland.
Even though the number of incidents increased and peaked in the first half of the given time period, it declined rapidly in the remaining time.