| Value | Category | Cases | |
|---|---|---|---|
| 1957 | 10 |
0.1%
|
|
| 1958 | 169 |
1.6%
|
|
| 1959 | 203 |
2%
|
|
| 1960 | 143 |
1.4%
|
|
| 1961 | 128 |
1.2%
|
|
| 1962 | 311 |
3%
|
|
| 1963 | 143 |
1.4%
|
|
| 1964 | 150 |
1.4%
|
|
| 1965 | 215 |
2.1%
|
|
| 1966 | 150 |
1.4%
|
|
| 1967 | 349 |
3.4%
|
|
| 1968 | 206 |
2%
|
|
| 1969 | 295 |
2.8%
|
|
| 1970 | 234 |
2.3%
|
|
| 1971 | 229 |
2.2%
|
|
| 1972 | 434 |
4.2%
|
|
| 1973 | 212 |
2%
|
|
| 1974 | 242 |
2.3%
|
|
| 1975 | 319 |
3.1%
|
|
| 1976 | 202 |
1.9%
|
|
| 1977 | 495 |
4.8%
|
|
| 1978 | 241 |
2.3%
|
|
| 1979 | 372 |
3.6%
|
|
| 1980 | 324 |
3.1%
|
|
| 1981 | 272 |
2.6%
|
|
| 1982 | 489 |
4.7%
|
|
| 1983 | 365 |
3.5%
|
|
| 1984 | 312 |
3%
|
|
| 1985 | 363 |
3.5%
|
|
| 1986 | 323 |
3.1%
|
|
| 1987 | 412 |
4%
|
|
| 1988 | 334 |
3.2%
|
|
| 1989 | 413 |
4%
|
|
| 1990 | 362 |
3.5%
|
|
| 1991 | 409 |
3.9%
|
|
| 1992 | 500 |
4.8%
|
|
| 9997 | Inconsistent | 1 |
0%
|
| 9998 | DK year | 39 |
0.4%
|