Describing a line graph The diagram shows how the disease X affected the country Y along 10 years, from '83 to '92. The numbers of cases remain steady between '83 to '85, growing in the next year and reaching 200 cases in '87. It dropped significantly from '87 to '88, then it rocketed sharply to its peak in '89, the country saw a booming of cases, reaching 400 people infected in that year. For the next two years, the number of cases suffered a small decrease, leveling off in 350 cases. By the year of '92, it had a drastically drop, reaching the bottom, with 0 cases, probably due to a vaccine developed in the previous years .