Table 1.

Summary statistics and years of data pertaining to the 1816 block groups in Philadelphia County.

	Mean (SD)	Median (IQR 25%, 75%)
All assaults (2002–2006)	5.28 (4.97)	4 [2, 7]
Gun assaults (2002–2006)	1.77 (2.25)	1 [0, 3]
Nongun assaults (2002–2006)	3.51 (3.50)	3 [1, 5]
No. of vacant properties (2002–2006)	12.53 (16.67)	6 [1, 18]
Total population (2004)	792.45 (507.09)	711.5 [455.5, 1003.5]
Median age (2004)	34.85 (8.35)	35 [30.6, 38.85]
Male: female ratio (2004)	0.89 (0.52)	0.9 [0.8, 0.9]
No. of black residents (2004)	353.22 (353.42)	248 [55.5, 575.5]
No. of Hispanic residents (2004)	69.18 (136.70)	20 [7, 62]
Median household income (2004)	35297 (20046)	33213 [22281, 44645]
No. of unemployed (2004)	42.18 (40.65)	31 [13, 61]
No. of with bachelor’s degree (2004)	78.88 (105.31)	43.84 [14.80, 100.84]
No. of single parent households (2004)	90.94 (60.56)	83 [46, 125]
No. of residential properties (2004)	253.40 (158.70)	238 [143, 340]

^*SD: standard deviation; IQR: interquartile range.