Here is a list of some of the significant droppers during the period by number of positions, what position the song fell to & what position it fell from:
14 15 1 Nothing From Nothing - Billy Preston (1974)
14 15 1 Then Came You - Dionne Warwick And The Spinners (1974)
11 12 1 Can't Get Enough Of Your Love, Babe - Barry White (1974)
11 12 1 Rock Me Gently - Andy Kim (1974)
11 12 1 You Haven't Done Nothin - Stevie Wonder (1974)
11 12 1 You Ain't Seen Nothing Yet - Bachman-Turner Overdrive (1974)
11 12 1 Whatever Gets You Thru The Night - John Lennon & The Plastic Ono Nuclear Band (1974)
17 19 2 Float On - The Floaters (1977)
20 23 3 Sexual Healing - Marvin Gaye (1983)
18 21 3 Love So Right - The Bee Gees (1976)
15 18 3 Annie's Song - John Denver (1974)
15 18 3 How Long - Ace (1975)
15 18 3 Moonlight Feels Right - Starbuck (1976)
15 18 3 Lost In Love - Air Supply (1980)
22 26 4 Beach Baby - First Class (1974)
21 25 4 Tin Man - America (1974)
21 25 4 Lowdown - Boz Scaggs (1976)
25 30 5 Some Kind Of Wonderful - Grand Funk (1975)
21 26 5 Still The One - Orleans (1976)
21 26 5 With You I'm Born Again - Billy Preston And Syreeta (1980)
20 25 5 Poetry Man - Phoebe Snow (1975)
36 42 6 Even The Nights Are Better - Air Supply (1982)
41 48 7 Steppin' Out (Gonna Boogie Tonight) - Tony Orlando & Dawn (1974)
26 33 7 Never My Love - Blue Swede (1974)
26 33 7 Love Rollercoaster - The Ohio Players (1976)
26 33 7 Kiss You All Over - Exile (1978)
36 44 8 Sweet Home Alabama - Lynyrd Skynyrd (1974)
23 31 8 Tryin' To Live My Life Without You - Bob Seger & The Silver Bullet Band (1981)
23 31 8 Rock The Casbah - The Clash (1983)
27 36 9 Waiting For A Girl Like You - Foreigner (1982)
26 35 9 Back Stabbers - The O'Jays (1972)
26 35 9 Whenever I Call You "Friend" - Kenny Loggins (1978)
49 59 10 Love Is In Control (Finger On The Trigger) - Donna Summer (1982)
38 48 10 Abracadabra - The Steve Miller Band (1982)
37 47 10 Get Down On It - Kool And The Gang (1982)
32 42 10 Carefree Highway - Gordon Lightfoot (1974)
72 92 20 The Beatles' Movie Medley - The Beatles (1982)
68 89 21 Superstar - The Carpenters (1971)
68 90 22 Still In Saigon - Charlie Daniels Band (1982)
67 85 18 Nobody Said It Was Easy - Le Roux (1982)
I found this near the bottom of this page:
www.ukmix.org/forums/viewtopic.php?t=13100