Year

Mean

Minimum

Maximum

Year

Mean

Minimum

Maximum

Year

Mean

Minimum

Maximum

1956

245.06

136.47

351.19

1976

243.54

119.79

337.48

1996

278.82

138.24

398.96

1957

256.42

158.08

413.65

1977

271.64

213.89

332.08

1997

252.24

172.36

368.83

1958

243.08

102.72

334.09

1978

253.10

158.26

327.88

1998

268.57

186.87

377.88

1959

234.32

165.23

374.91

1979

221.80

111.09

395.10

1999

274.88

182.86

418.80

1960

271.03

170.02

393.48

1980

240.94

140.16

340.74

2000

250.17

141.92

325.56

1961

272.20

216.85

370.95

1981

268.23

184.37

342.18

2001

258.87

170.82

352.81

1962

268.49

174.43

371.72

1982

201.89

82.75

343.39

2002

263.42

203.82

333.61

1963

235.06

145.33

317.53

1983

273.89

167.80

334.67

2003

251.50

203.82

333.61

1964

273.34

157.35

382.23

1984

253.62

175.54

379.11

2004

256.18

203.82

333.61

1965

219.27

79.42

388.01

1985

278.95

213.49

329.46

2005

255.32

142.15

341.30

1966

268.52

138.21

453.26

1986

248.17

165.43

398.32

2006

251.98

165.74

333.61

1967

264.49

172.68

363.09

1987

223.63

112.91

374.83

2007

265.49

155.02

375.12

1968

232.71

118.47

350.52

1988

266.14

202.05

362.54

2008

265.05

174.25

351.64

1969

262.85

191.72

345.35

1989

265.76

194.16

365.42

2009

275.56

203.82

418.85

1970

293.40

188.40

419.12

1990

266.07

191.38

359.25

2010

297.76

181.87

461.59

1971

280.67

175.70

334.14

1991

240.23

108.17

336.79

2011

263.47

170.02

354.29

1972

212.78

65.16

374.90

1992

227.83

109.13

324.48

2012

274.63

189.96

373.84

1973

297.41

177.06

435.92

1993

203.56

74.11

349.63

2013

259.63

203.82

333.61

1974

243.77

120.97

369.68

1994

202.31

97.45

316.28

2014

267.24

152.87

484.31

1975

284.51

195.82

383.66

1995

255.87

144.73

361.30

2015

245.64

137.87

333.61

2016

260.45

203.82

333.61