PM10-2.5 Distribution Statistics for 2009


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Table 1. The following table shows summary statistics for PM10-2.5. The first column identifies the county and site name; the second column shows the number of valid samples; the third column shows the percentage of these samples for which negative concentration values were computed; the 4th through 7th columns show indicated percentile statistics, 25%, 50%, 75% and 98%; and the 8th column shows the arithmetic mean value.

County / SiteNo. Obs.% neg.25th %50th %75th %98th %Arith. Mean
Mecklenburg / Garinger1120.04.025.206.8210.785.55
Mecklenburg / Montclaire 11100.04.205.858.3016.936.96
Mecklenburg / Montclaire 2540.03.656.208.7516.676.67
Wake / Millbrook1013.02.784.967.0513.645.26
Catawba / Hickory*585.23.136.039.3616.116.59
Guilford / Greensboro*5411.11.694.475.6211.323.89
Cumberland / Fayetteville*5315.11.823.767.0410.524.08

* Computed using nonmatching PM10 and PM2.5 monitor methods.