Table 3. Comparison of yearly outdoor crime rates by percentage of urban trees within block group

Percentage of urban trees	N	Mean of yearly outdoor crime rates per acre	Standard deviation	F-value	Prob>F
Tree 0%∼25%(Low)	127	1.201	1.620	17.67	<0.000
Tree 25%∼50%(Mid)	271	0.741	0.987
Tree>50%(High)	59	0.146	0.250
Total	457	0.792	1.188