HD stopped showing regularly in January 1984.

HD came back three months later for three episodes, which included the final episode. But the final episode was not the final episode shown.

Four episodes were shown in the summer and the final episode shown was in September 1984.

Would anyone know the ratings for the final year?

I don't know exactly what they were, but the show wasn't in the top 30 that season for the first time since season two.

happy days season 11 ran in a very strange order in the last season they aired the final episode PASSAGES in early may 1984 as an hour special the show was off the air untill sometime in july and then the night was changed to thursday the episodes that were aired in july were recorded but unaired before may 1984 i think they aired all the remaining unaired episodes untill either the end of aug or the first week of sept.the final episode PASSAGES as far as i know only aired once on abc.im really not sure about the ratings but i know they were low for the final season.the last episode shown on abc was FONZIE SPOTS.