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Table representation of search results timeline featuring number of search results per year.
| Year | Number of Results |
|---|---|
| 1968 | 2 |
| 1969 | 2 |
| 1970 | 2 |
| 1971 | 4 |
| 1972 | 3 |
| 1973 | 7 |
| 1974 | 12 |
| 1975 | 12 |
| 1976 | 14 |
| 1977 | 15 |
| 1978 | 12 |
| 1979 | 11 |
| 1980 | 5 |
| 1981 | 9 |
| 1982 | 4 |
| 1983 | 6 |
| 1984 | 7 |
| 1985 | 7 |
| 1986 | 7 |
| 1987 | 11 |
| 1988 | 6 |
| 1989 | 4 |
| 1990 | 5 |
| 1991 | 8 |
| 1992 | 1 |
| 1993 | 1 |
| 1994 | 3 |
| 1996 | 1 |
| 1997 | 2 |
| 2000 | 3 |
| 2001 | 1 |
| 2003 | 2 |
| 2012 | 1 |
| 2015 | 1 |
| 2016 | 2 |
| 2017 | 2 |
| 2018 | 1 |
| 2019 | 2 |
| 2021 | 2 |
| 2023 | 2 |