Year range Lassie

Currently, the year range for Lassie is listed as 1954-1974 (https://www.imdb.com/title/tt0046617/reference/). However, there are only episodes/seasons listed for the period 1954-1973. Apart from that, TMDb also has a year range of 1954-1973: https://www.themoviedb.org/tv/5368-lassie, just as classictv.com: https://www.classic-tv.com/shows/decade/1960s/lassie (the same goes for Wikipedia: https://en.wikipedia.org/wiki/Lassie_(1954_TV_series)). Can a staffer look into this and change the year range?