Phase | Solar cycle 21 | Solar cycle 22 | Solar cycle 23 | ||||||
Year | Winter | Summer | Year | Winter | Summer | Year | Winter | Summer | |
Minimum | 1976 | 14 | 15 | 1985 | 16 | 21 | 1996 | 13 | 19 |
Increasing | 1977 | 11 | 8 | 1986 | 25 | 29 | 1997 | 21 | 8 |
1978 | 9 | 10 | 1987 | 30 | 8 | 1998 | 14 | 17 | |
1979 | 28 | 7 | 1988 | 4 | 7 | 1999 | 14 | 26 | |
1989 | 18 | 10 | 2000 | 16 | 31 | ||||
Maximum | 1980 | 17 | 24 | 1990 | 20 | 10 | 2001 | 28 | 9 |
Decreasing | 1981 | 12 | 6 | 1991 | 29 | 6 | 2002 | 1 | 17 |
1982 | 17 | 1 | 1992 | 4 | 26 | 2003 | 12 | 19 | |
1983 | 4 | 9 | 1993 | 21 | 9 | 2004 | 22 | 4 | |
1984 | 21 | 24 | 1994 | 23 | 22 | 2005 | 21 | 7 | |
1995 | 12 | 13 |