Yea r

Adder Numbers

Yea r	Sites Surveyed	Sites with Adders	Matur e Males	Mature Females	Total	Average per Site
1990	56	50	185	55	240	4.8
1991	76	61	211	56	267	4.4
1992	78	55	159	33	192	3.5
1993	80	59	186	70	256	4.3
1994	76	50	153	29	182	3.6
1995	76	44	103	14	117	2.6
1996	80	41	112	32	144	3.5
1997	84	44	102	31	133	3
1998	85	42	103	34	137	3.3
1999	67	35	100	20	120	3.4
2000	87	24	69	13	82	3.4
2001	20*	18	54	9	63	3.8
2002	20**	13	36	17	53	4
2003	20**	9	26	10	36	4
2004	20	11	30	10	40	3.6
* Limited by FMD restrictions			**Surveys restricted to selected sites