Metropolitan Area/Study Period | Summer Mean (SD) | Winter Mean (SD) | Overall Mean (SD) |
---|---|---|---|
PMA 1986–2000 | 11.9 (3.6) | 17.4 (5.1) | 14.2 (4.9) |
LMA 1986–2000 | 24.1 (6.0) | 36.0 (8.2) | 29.1 (8.4) |
PMA 2001–2005 | 14.3 (11.4) | 9.2 (6.4) | 11.7 (9.8) |
LMA 2001–2005 | 23.3 (6.2) | 34.8 (8.2) | 27.8 (8.4) |