As I know,
users of wikipedia can change their status by becoming helper,
admin or joining other groups. Since when, the user groups like this data
showed, the date this date collected? How I am supposed to do if I want the
data showing the change of user status?
You'd need to check the data from the logging table to see when
user rights were changed on individual users.
Also note that some information will be inside meta logs table, and
really old sysopping actions won't be recorded at all.