The following are the sizes of particles of cement dust (given to the nearest hundredth of a micron) in a cement factory:

16.12	10.48	11.12	16.18	18.13	19.10	13.21	10.12
21.18	15.12	10.11	13.31	18.61	11.43	18.26	13.77
13.24	12.16	17.19	11.36	12.53	13.25	10.67	15.45
14.28	14.32	15.18	14.21	10.20	15.64	11.68	18.76
19.32	17.50	11.46	20.59	16.38	21.42	16.27	21.30
16.12	10.55	11.49	15.48	11.62	13.54	13.69	16.72
15.11	14.33	17.23	17.22	19.37	10.41	18.28	19.29
21.23	12.56	12.57	11.60	15.24	21.65	20.70	11.44
12.22	19.34	20.35	19.47	21.63	19.40	19.75	21.71
15.19	18.51	10.58	13.52	11.39	13.66	21.73	11.74

Group these figures into a table with a suitable number of equal classes and construct a histogram.