Return period (years)

10

20

50

100

500

Return level (s)

20.20

19.79

19.51

19.39

19.25

Standard error

0.180

0.140

0.0976

0.0903

0.123

95% CI

(19.85, 20.55)

(19.51, 20.06)

(19.31, 19.69)

(19.21, 19.56)

(19.01, 19.49)