Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[20,30[	25	1	0.041667	0.041667	0.004167
[30,40[	35	7	0.291667	0.333333	0.029167
[40,50[	45	6	0.25	0.583333	0.025
[50,60[	55	6	0.25	0.833333	0.025
[60,70[	65	2	0.083333	0.916667	0.008333
[70,80[	75	1	0.041667	0.958333	0.004167
[80,90]	85	1	0.041667	1	0.004167