Year	January	February	March	September	March trend	September trend
1979	15.84	16.57	16.85	8	16.54	8.7
1980	15.59	16.46	16.51	8.75	16.5	8.61
1981	15.43	16.08	16.14	8.17	16.45	8.52
1982	15.72	16.46	16.53	8.25	16.41	8.43
1983	15.45	16.42	16.53	8.45	16.37	8.34
1984	14.91	15.67	15.98	7.88	16.33	8.25
1985	15.11	15.83	16.32	7.8	16.29	8.16
1986	15.27	16.21	16.3	8.15	16.25	8.06
1987	15.51	16.45	16.17	8.15	16.2	7.97
1988	15.58	16	16.35	8.16	16.16	7.88
1989	15.22	15.89	15.86	7.75	16.12	7.79
1990	15.14	16	16.34	6.94	16.08	7.7
1991	14.79	15.65	15.8	7.24	16.04	7.61
1992	15.3	15.97	16.04	8.24	15.99	7.52
1993	15.46	16.14	16.22	7.32	15.95	7.43
1994	15.19	16.02	15.97	8.02	15.91	7.34
1995	15.06	15.64	15.66	6.82	15.87	7.24
1996	14.61	15.55	15.53	8.42	15.83	7.15
1997	14.97	15.86	15.9	7.42	15.79	7.06
1998	15.12	16.1	16.02	7.5	15.74	6.97
1999	14.84	15.66	15.71	7.18	15.7	6.88
2000	14.72	15.61	15.64	7.28	15.66	6.79
2001	14.76	15.68	15.85	7.59	15.62	6.7
2002	14.89	15.77	15.75	6.59	15.58	6.61
2003	14.78	15.55	15.84	6.89	15.53	6.52
2004	14.43	15.27	15.31	6.64	15.49	6.42
2005	14.04	14.77	15.04	6.19	15.45	6.33
2006	13.91	14.67	14.77	6.56	15.41	6.24
2007	14.14	14.91	14.91	4.96	15.37	6.15
2008	14.24	15.27	15.44	5.39	15.33	6.06
2009	14.22	15.06	15.26	5.89	15.28	5.97
2010	13.97	14.88	15.41	5.55	15.24	5.88
2011	13.79	14.63	14.87	5.12	15.2	5.79
2012	14.04	14.9	15.47	4.15	15.16	5.69
2013			15.43	6.16	15.12	5.6
2014			15.33	6.3	15.07	5.51