Table 1. Summary statistics of daily death numbers, air pollution concentrations and weather conditions in Beijing, China (2009∼2010).

	Mean ± SD		Min*	P(25)**	P(50)**	P(75)**	Max***
Daily deathcounts
Nonaccidental	200.4±28.7		135	180	198	221	282
Cardiovascular	101.0±19.8		39	86	99	115	80
Respiratory	20.6±6.0		7	16	20	24	47
Air pollutants concentrationsa
CO (mg/m3)		1.54±1.01	0.27	0.87	1.24	1.84	7.79
NO2 (µg/m3)		55.02±24.04	9.90	39.27	50.41	64.36	180.67
PM10 (µg/m3)		121.04±75.30	4.91	69.00	107.00	149.00	651.18
Weather
Temperature(°C)		13.0±11.7	−12.5	1.7	14.7	24.3	34.5
Humidity (%)		51.0±19.2	13	35	52	67	92
Barometricpressure (hPa)		1012±9.8	989.7	1004.4	1011.2	1019.2	1037.1

^aTwenty-four-hour average for CO, NO₂ and PM₁₀.

^*minimum.

^**the 25^th, 50^th (median) and 75^th percentile, respectively.

^***maximum.