This bar graph chart shows results from the survey. The graph shows the number of cases and outbreaks for each year. Below are the results in tabular format.
| 1970 | 1971 | 1972 | 1973 | 1974 | 1975 | 1976 | 1977 | 1978 | 1979 | 1980 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| # Cases | 9 | 16 | 6 | 20 | 26 | 15 | 21 | 79 | 13 | 8 | 18 |
| # Outbreaks | 5 | 6 | 3 | 7 | 17 | 11 | 10 | 16 | 10 | 7 | 14 |