PM10-2.5 Distribution Statistics for 2012


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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 4ththrough 7th columns show indicated percentile statistics, 25%, 50%, 75% and 98%; and the 8th column shows the arithmetic mean value.

County / Site No. Obs. % neg. 25th % 50th % 75th % 98th % Arith. Mean
Mecklenburg / Garinger 114 0.0 3.97 5.75 7.48 13.15 6.10
Mecklenburg / Montclaire 1 118 0.0 4.32 6.45 9.57 19.91 7.61
Mecklenburg / Montclaire 2 61 0.0 3.70 5.20 9.30 21.56 7.11
Durham / Durham 112 0.0 3.91 5.56 6.86 15.67 5.91
Wake / Millbrook 119 0.0 3.79 5.33 7.04 12.45 5.66
Catawba / Hickory* 56 0.0 4.25 6.60 8.87 16.39 6.87
Forsyth / Winston-Salem* 338 3.8 3.21 4.88 6.62 12.11 4.99
Guilford / Greensboro* 50 10.0 2.79 5.22 8.28 13.68 5.42
Martin / Jamesville* 59 1.7 4.06 6.25 9.38 13.28 6.45
Cumberland / Fayetteville* 58 1.7 4.07 6.51 7.96 12.57 6.14

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