Table 1.
PAHyear | Annual Number Observations | Annual Mean | Standard deviation | Annual Median | Winter Number Observations | Winter mean | Winter Standard deviation | Winter Median | Ratio of Winter to Annual means |
---|---|---|---|---|---|---|---|---|---|
2001 | 365 | 10.86 | 12.84 | 4.74 | 120 | 24.67 | 13.98 | 22.06 | 2.27 |
2002 | 365 | 9.14 | 10.02 | 4.48 | 120 | 19.76 | 10.85 | 18.9 | 2.16 |
2003 | 365 | 8.49 | 8.99 | 4.08 | 120 | 18.03 | 9.66 | 16.74 | 2.12 |
2004 | 324 | 5.25 | 6.66 | 2.43 | 79 | 13.48 | 8.83 | 11.13 | 2.57 |
2005 | 365 | 4.20 | 4.44 | 2.43 | 120 | 8.18 | 5.68 | 6.24 | 1.95 |
2006 | 365 | 4.09 | 4.07 | 2.29 | 120 | 8.16 | 4.75 | 7.38 | 1.99 |
2007 | 296 | 5.41 | 4.24 | 3.72 | 120 | 8.08 | 5.01 | 7.26 | 1.49 |
2008 | 273 | * | * | * | 119 | 11.28 | 6.76 | 9.46 | * |
2009 | 61 | * | * | * | 61 | * | * | * | * |
2010 | 0 | * | * | * | 0 | * | * | * | * |
2011 | 145 | * | * | * | 5 | * | * | * | * |
2012 | 178 | * | * | * | 116 | 10.33 | 6.25 | 9.90 | * |
2013 | 98 | * | * | * | 98 | 7.61 | 4.80 | 6.93 | * |
2014 | 195 | * | * | * | 0 | * | * | * | * |
2015 | 362 | 3.33 | 3.68 | 1.54 | 117 | 7.07 | 4.32 | 6.01 | 2.12 |
2016 | 366 | 3.86 | 4.43 | 1.57 | 121 | 8.48 | 5.04 | 7.70 | 2.20 |
2017 | 354 | 2.95 | 3.54 | 1.46 | 109 | 6.10 | 4.72 | 4.67 | 2.06 |
2018 | 365 | 4.11 | 4.66 | 1.82 | 120 | 8.72 | 5.68 | 7.07 | 2.12 |
2019 | 212 | * | * | * | 120 | 7.50 | 5.07 | 6.37 | * |
Insufficient measurement days for a valid average.