Time series	1976-2011			1976-1999			2000-2011
Time series	Sig.	Slope	km/36 yrs.	Sig	Slope	km/24yrs.	Sig.	Slope	km/12yrs.
Annual				***	0.024	0.60	***	−0.16	−1.92
January				***	0.027	0.65	**	−0.14	−1.76
February				***	0.031	0.75	***	−0.12	−1.44
March				+	0.021	0.50	**	−0.13	−1.56
April				**	0.033	0.79	**	−0.17	−2.04
May				+	0.025	0.60	**	−0.15	−1.80
June				**	0.035	0.84	***	−0.18	−2.16
July				**	0.025	0.60	**	−0.16	−1.92
August				***	0.020	0.48	**	−0.07	−0.84
September	+	0.007	0.25	***	0.017	0.41	*	−0.04	−0.57
October	**	0.010	0.36	***	0.025	0.60
November				***	0.014	0.33
December	+	0.009	0.32	**	0.030	0.72
Winter				***	0.027	0.65	**	−0.18	−2.16
Spring				**	0.030	0.73	***	−0.14	−1.68
Summer	**	0.013	0.48	***	0.026	0.63	**	−0.04	−0.48
Fall				***	0.016	0.40