The chart illustrates the number of cases of X illness over the period from 1983 to 1990.
Overall, the number of cases fluctuated considerably during this period. There were periods of gradual increase and moderate decline, followed by a rapid rise that peaked in 1989, after which the figures fell sharply by the end of the period.
The number of cases of X illness started at 100 in 1983, followed by a levelling off in 1984. After that, the cases rose gradually to 200 by 1987, before declining moderately to 100 in 1988. Subsequently, the number of cases increased rapidly, peaking at 400 in 1989. In 1990, there was a slight drop to 350, which remained stable throughout the year. Finally, the figures fell sharply, reaching a low by the end of the period.
