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	Annual Toxics Summary Simi Valley-Cochran Street FAQs Zirconium nanograms per cubic meter

Year	Months Present	Minimum	Median	Mean	90th Percentile	Maximum	Standard Deviation	Number of Observations	Detection Limit
2024		0.65	0.65	*	2.4	2.6	0.75	13	1.3
2023		0.65	0.65	1.14	2.0	2.2	0.57	29	1.3
2022		0.65	0.65	1.21	2.2	2.5	0.66	31	1.3
2021		0.65	1.6	*	2.8	3.2	0.83	22	1.3
2020		0.65	*	*	*	2.3	0.76	8	1.3
2019		0.65	1.5	1.52	2.8	3.2	0.85	29	1.3
2018		0.65	0.65	1.25	2.8	3.8	0.93	34	1.3
2017		0.65	0.65	1.23	2.9	3.6	0.95	29	1.3
2016		0.65	1.4	*	2.6	3.9	0.93	28	1.3
2015		0.65	0.65	0.96	1.5	2.5	0.48	30	1.3
2014		0.75	0.75	1.10	2.3	2.6	0.66	30	1.5
2013		0.75	0.75	*	0.75	0.75	0.04	26	1.5
2012		0.75	0.75	0.79	0.75	1.6	0.16	28	1.5
2011		0.75	0.75	0.75	0.75	0.75	0.00	30	1.5
2010		0.75	0.75	*	0.75	1.5	0.15	25	1.5
2009		0.75	0.75	0.91	1.5	2.8	0.45	31	1.5
2008		*	*	*	*	*	*	0	*
2007		0.75	0.75	*	0.75	3.5	0.70	24	1.5
2006		*	*	*	*	*	*	0	*
2005		*	*	*	*	*	*	0	*
2004		*	*	*	*	*	*	0	*
2003		1	*	*	*	4.0	1.41	4	2.0
2002		1	4.0	4.31	6.6	15	3.07	29	2.0
2001		1	4.0	*	6.4	63	12.3	24	2.0
2000		1	2.0	*	4.6	5.0	1.44	15	2.0
1999		1	3.0	*	6.0	8.0	1.84	27	2.0
1998		1	2.0	2.26	4.0	6.0	1.49	29	2.0
1997		1	2.0	2.69	4.0	8.0	1.82	31	2.0
1996		1	3.0	2.63	5.0	5.0	1.42	29	2.0
1995		1	2.0	3.14	6.0	10	2.40	31	2.0
1994		1	2.0	*	5.4	17	3.30	27	2.0
1993		1	3.0	3.47	6.0	10	2.36	31	2.0
1992		1	1	*	5.9	8.0	2.19	22	2.0
1991		1	4.0	3.75	6.3	8.0	1.99	28	2.0
1990		1	6.0	*	8.5	10	2.60	16	2.0
1989		*	*	*	*	*	*	0	*

	Notes:	Values below the Limit of Detection (LoD) assumed to be ½ LoD. Means and risks shown only for years with data in all 12 months. "*" means there was insufficient or no data available to determine the value.