Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[-20,-15[	-17.5	3	0.045455	0.045455	0.009091
[-15,-10[	-12.5	3	0.045455	0.090909	0.009091
[-10,-5[	-7.5	12	0.181818	0.272727	0.036364
[-5,0[	-2.5	15	0.227273	0.5	0.045455
[0,5[	2.5	18	0.272727	0.772727	0.054545
[5,10[	7.5	3	0.045455	0.818182	0.009091
[10,15[	12.5	9	0.136364	0.954545	0.027273
[15,20]	17.5	3	0.045455	1	0.009091