Year	Cadmium (t)	Cadmium index	Lead (t)	Lead index	Mercury (t)	Mercury index
1990	260.6	100	24307.8	100	240.5	100
1991	242.8	93	18875.7	78	222.6	93
1992	231.8	89	15109.4	62	209.3	87
1993	220.5	85	13656.9	56	183.2	76
1994	209.5	80	12352.5	51	176.4	73
1995	207.2	79	11323.5	47	175.0	73
1996	206.0	79	9861.0	41	163.4	68
1997	199.3	76	8958.8	37	152.5	63
1998	160.7	62	8046.7	33	143.9	60
1999	161.3	62	6969.9	29	135.0	56
2000	138.8	53	4840.7	20	120.3	50
2001	134.1	51	4172.9	17	113.9	47
2002	127.0	49	3353.6	14	109.5	46
2003	121.3	47	3221.8	13	105.1	44
2004	119.6	46	3171.0	13	103.9	43
2005	118.7	46	3100.8	13	104.3	43
2006	119.2	46	3086.3	13	102.5	43
2007	107.4	41	3012.8	12	102.3	43
2008	108.4	42	2959.6	12	97.5	41
2009	97.8	38	2487.8	10	84.1	35
2010	101.2	39	2695.1	11	82.1	34
2011	92.8	36	2597.3	11	81.1	34