YEAR | AVERAGE HUB HEIGHTa (metres; full certainty) | STANDARD DEVIATION | AVERAGE HUB HEIGHTb (metres; partial certainty) | STANDARD DEVIATION |
1983 | 22.80 | 0.00 | n/a | n/a |
1984 | 24.00 | 0.00 | 24 | .00 |
1985 | 24.39 | 0.29 | n/a | n/a |
1986 | n/a |
| 25.31 | 6.80 |
1987 | n/a |
| n/a | n/a |
1988 | 23.00 | .00 | n/a | n/a |
1989 | n/a | n/a | n/a | n/a |
1990 | n/a | n/a | 29.32 | 2.76 |
1991 | n/a | n/a | n/a | n/a |
1992 | 43.00 | . | 40 | . |
1994 | n/a | n/a | 40 | .00 |
1995 | 39.77 | 1.52 | 25 | . |
1996 | 50.00 | . | n/a | n/a |
1997 | 30.50 | 0.00 | 44.04 | 6.33 |
1998 | 52.29 | 3.56 | n/a | n/a |
1999 | 57.23 | 7.23 | 61.05 | 6.90 |
2000 | 57.56 | 9.29 | 30.00 | . |
2001 | 57.10 | 7.81 | 65.41 | 5.79 |
2002 | 62.74 | 5.83 | 53.25 | 37.83 |
2003 | 66.70 | 7.38 | 70.94 | 7.56 |
2004 | 67.63 | 9.39 | 63.32 | 2.43 |
2005 | 75.24 | 8.06 | 74.91 | 9.72 |