Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[-5,0[	-2.5	9	0.125	0.125	0.025
[0,5[	2.5	11	0.152778	0.277778	0.030556
[5,10[	7.5	15	0.208333	0.486111	0.041667
[10,15[	12.5	28	0.388889	0.875	0.077778
[15,20]	17.5	9	0.125	1	0.025