Try this: This guy has a link that lists all the number 1 hits for each year of the 70's.You can also look up each artist.
http://www.geocities.com/cstuff84/
3. Top Hits of the 1970s
The definitive reference for American chart hits of the 1970s
www.geocities.com
1972
Don MacLean--American Pie
Al Green--Let's Stay Together
Nilsson--Without You
Neil Young--Heart of Gold
America--A Horse With No Name
Roberta Flack--The First Time Ever I Saw Your Face
Chi-Lites--Oh Girl
Staple Singers--I'll Take You There
Sammy Davis, Jr.--The Candy Man
Neil Diamond--Song Sung Blue
Bill Withers--Lean On Me
Gilbert O'Sullivan--Alone Again (Naturally)
Looking Glass--Brandy (You're a Fine Girl)
Three Dog Night--Black & White
Mac Davis--Baby, Don't Get Hooked On Me
Michael Jackson--Ben
Chuck Berry--My Ding-a-Ling
Johnny Nash--I Can See Clearly Now
Temptations--Papa Was a Rollin' Stone
Helen Reddy--I Am Woman
Billy Paul--Me and Mrs. Jones
1973
Carly Simon--You're So Vain
Stevie Wonder--Superstition
Elton John--Crocodile Rock
Roberta Flack--Killing Me Softly With His Song
O'Jays--Love Train
Vicki Lawrence--The Night the Lights Went Out in Georgia
Dawn featuring Tony Orlando--Tie a Yellow Ribbon Round the Ole Oak Tree
Stevie Wonder--You Are the Sunshine of My Life
Edgar Winter Group--Frankenstein
Paul McCartney & Wings--My Love
George Harrison--Give Me Love (Give Me Peace On Earth)
Billy Preston--Will it Go Round in Circles
Jim Croce--Bad, Bad Leroy Brown
Maureen McGovern--The Morning After
Diana Ross--Touch Me In the Morning
Stories--Brother Louie
Marvin Gaye--Let's Get It On
Helen Reddy--Delta Dawn
Grand Funk--We're an American Band
Cher--Half-Breed
Rolling Stones--Angie
Gladys Knight & the Pips--Midnight Train to Georgia
Eddie Kendricks--Keep On Truckin'
Ringo Starr--Photograph
Carpenters--Top of the World
Charlie Rich--The Most Beautiful Girl
Jim Croce--Time in a Bottle