you've missed 3 great films from 78

Beauty and the Beast
the shout
Crazed

also a few other good films
Damned in Venice
Coma
The Death Train
Night Cries
The Medusa Touch
The Night Nurse
The World Beyond
Alien Zone

78 would be in the top 10, but Still can't touch 72 or 73 though

72
The Last House on the Left
Diabel
Morgiana
The Screaming Woman
Arcana
What the Peeper Saw
The Other
Private Parts
The Possession of Joel Delaney
Blacula
When Michael Calls
So Sweet, So Dead
La goulve
The Etruscan Kills Again
Images
Neither the Sea Nor the Sand
Home for the Holidays
Dear Dead Delilah
Night of the Devils
Demons of the Mind
A Reflection of Fear
The Flesh and Blood Show
Crawlspace
The Red Queen Kills Seven Times
A Warning to the Curious
Terror House
Don't Torture a Duckling
What Have You Done to Solange?
Tales from the Crypt
Dr. Phibes Rises Again
All the Colors of the Dark
The Night Stalker

Im excluding Horror Express, Your Vice is a Locked Door and Only I Have the Key, All the Colors of the Dark, Frenzy, Baron Blood, Red Queen Kills 7 Times, The Gore Gore Girls, Seven Blood Stained Orchids, Death Line, Dracula A.D. 1972, Children Shouldn't Play with Dead Things, Tower of Evil, Hungry Wives, Pink Flamingos, Deliverence,, The Cannibal Man, The Asphyx , Gargoyles, Vampire Circus, Asylum, The Stone Tape, Sisters

these are my opinion, if we take IMDB voters opinions
https://www.imdb.com/search/title?genres=horror&release_date=1972,1972&sort=user_rating,desc&title_type=feature,tv_movie,video 50th title = 6.1 rating
https://www.imdb.com/search/title?genres=horror&release_date=1978,1978&sort=user_rating,desc&title_type=feature,tv_movie,video 50th title = 5.6 rating

of the zombieCPA's IMDB horror board's top 500,
1972 16 titles in the top 500
1978 6 titles in the top 500