The graph below gives information about the number of cases of diarrhea in Mashhad between 1983 and 1992

The line graph given illustrates the number of people with diarrhea in Mashhad from 1983 to 1992.

Overall, the number of cases of diarrhea tended to increase from 1983 to 1987. after that, it suddenly grew in 1989 and decreased dramatically at the end of the period shown.

it stood at 100 in 1983 and remained relatively unchanged in 1984. Since then, it started to rise gradually in three years and stood at above 200 cases in 1987. This was followed by another increase, though much steeper, it suddenly went up dramatically with 400 cases of diarrhea, reaching a peak of the period shown. But in the following four years, in 1990 and 1991 came with a small dropped about 350 cases, after which the number of cases plummeted enormously and leveled off to zero cases in 1992.