Reading this suggestion https://en.numista.com/forum/topic159803.html we know that the page history records the most of the changed values in the page (sections: overall information, technical data, obverse, reverse, edge, mints, comments and references), except changes in the year lines (section: varieties). The sources field (that contains sources and comments about the changes made in the fields of the page and the year lines) is also recorded.
With the current information recorded in the page history, referees and admins can see all values for any field over time, and the reasons for their change. Except in the case of the year lines fields, that know the reasons for their change but do not know the values over time).
This is a problem. I suggest that the page history records the changes in the year lines.