年度	24 h	48 h	>48 h	χ²	P
2013	82 (71.30%)	19 (16.52%)	14 (12.18%)	8.612	0.013 ^a
2014	21 (95.46%)	1 (4.54%)	0		0.667^b
2015	11 (100.00%)	0	0	7.047	0.029 ^c
2016	13 (86.67%)	2 (13.33%)			0.323^d
2017	19 (86.36%)	3 (13.64%)			0.683^e
					0.534 ^f