The graph illustrates data on the number of diarrhea cases in Mashhad over a period of almost a decade, from 1983 to 1992.
In the first year, 1983, the figures for registered diarrhea cases stood at approximately 100 and remained static in 1984. This was followed by negligible growth in 1985, which became the starting point of a considerable rise in the number of cases, reaching a little less than 200 in 1986. Following this sudden upturn, the figures slightly increased. However, this upward trend was abruptly broken by figures dropping significantly, just below the level as they were in the first two years. Despite this abrupt dip, in 1988, the number of cases skyrocketed, reaching its peak of roughly 400. During the next two years, the figures declined noticeably before leveling off at 350 cases. Remarkably, in 1992, the number of cases plummeted dramatically, going down to absolute 0.
Overall, for the first half of the decade, the figures for registered diarrhea cases remained relatively unchanged. Nevertheless, the rest of the years exhibited drastic changes in numbers, experiencing both a steep increase and a sharp drop in cases.