May Mean Temperatures

Year	No.Years	Act. Mean Temp	Cum. Mean Temp	Av. Mean Temp
1984	1	9.63	9.42	9.42
1985	2	9.99	19.41	9.71
1986	3	10.86	30.27	10.09
1987	4	9.79	40.06	10.02
1988	5	11.60	51.66	10.33
1989	6	13.29	64.95	10.83
1990	7	12.01	76.96	10.99
1991	8	10.77	87.73	10.97
1992	9	13.01	100.74	11.19
1993	10	11.24	111.98	11.20
1994	11	10.70	122.68	11.15
1995	12	11.77	134.45	11.20
1996	13	9.16	143.61	11.05
1997	14	11.83	155.44	11.10
1998	15	13.55	168.99	11.27
1999	16	13.20	182.19	11.39
2000	17	12.47	194.66	11.45
2001	18	12.53	207.19	11.51
2002	19	11.89	219.08	11.53
2003	20	12.15	231.23	11.56
2004	21	12.45	243.68	11.60
2005	22	11.82	255.50	11.61
2006	23	12.64	268.14	11.66
2007	24	12.77	280.91	11.70
2008	25	13.50	294.41	11.78
2009	26	12.50	306.91	11.80
2010	27	11.35	318.26	11.79
2011	28	12.60	330.86	11.82