Table 2.

Data description.

Pro	Quantity	Percent
0	28,769	87.12%
1	2834	8.58%
2	463	1.40%
3	207	0.63%
4	105	0.32%
5	70	0.21%
6–10	206	0.62%
11–15	175	0.53%
16–20	152	0.46%
21–27	43	0.13%
Sum	33,024	100%