The line graph illustrates the number of cases of diseases caused by the X virus in Australia over a 35-year period, starting from 1960 and ending in 1995.
Overall, the incidence of the virus experienced a substantial upward trend during the first fifteen years, reaching a plateau before plummeting to zero by 1990. The virus was most prevalent between 1975 and 1980.
In 1960, there were 50 reported cases of the X virus. This figure doubled to 100 by 1965 and continued to climb, reaching 200 cases by 1970. The most rapid growth occurred in the following five-year period, with cases surging to 500 by 1975. This peak level was maintained until 1980, representing the highest recorded incidence in the timeframe.
Following this period of stability, the number of cases began to fall. By 1985, the figure had decreased to 410. Subsequently, there was a dramatic decline, as the number of reported cases dropped to zero by 1990. This absence of cases persisted through 1995, indicating that the virus had been effectively eradicated in Australia by the end of the observed period.