Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[20,30[	25	15	0.092593	0.092593	0.009259
[30,40[	35	67	0.41358	0.506173	0.041358
[40,50[	45	69	0.425926	0.932099	0.042593
[50,60[	55	11	0.067901	1	0.00679