Table 2.

Basic situation of the sample

	Unit		Working years			Professional title	Positional title
	Hospital	Enterprise	5–10 years	11–20 years	More than 20 years	Advanced or above	Middle or above
First round	15	15	15	2	13	13	17
Second round	25	0	0	5	20	25	23
Third round	20	0	0	2	18	20	20