Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[0,20[	10	16	0.222222	0.222222	0.011111
[20,40[	30	12	0.166667	0.388889	0.008333
[40,60[	50	13	0.180556	0.569444	0.009028
[60,80[	70	16	0.222222	0.791667	0.011111
[80,100[	90	8	0.111111	0.902778	0.005556
[100,120[	110	4	0.055556	0.958333	0.002778
[120,140]	130	3	0.041667	1	0.002083