parse yyyy; yyyy; yyyy;.... pattern

[aaron-collier]

This pattern is found in AUC.

Should be able to return earliest_year and latest_year from a pattern like: "1990; 1991; 1992; 1993; 1994; 1995".

earliest_year() => 1990
latest_year() => 1995

[ndushay]

If this is added, it should probably be parse_with_delim because we also have date strings with comma separated dates.