Paula Abdul (55 weeks/8 songs = 6.9 weeks)
Rush Rush: 9 Weeks
Cold Hearted: 8 Weeks
Straight Up: 7 Weeks
Opposites Attract: 7 weeks
Blowing Kisses In The Wind: 7 weeks
Forever Your Girl: 6 Weeks
The Way That You Love Me: 6 weeks
The Promise of a New Day: 5 weeks
chart runs were so fast before SoundScan

BKITW was her only post-SS top 10 and it only peaked at #6 but stayed in the top 10 for as long as some of her pre-SS #1s.
Here are the girls pre-SoundScan top 10 runs
MARIAH (36 weeks/5 = 7.2 weeks)
I Don't Wanna Cry - 8 weeks
Someday - 7 weeks
Emotions - 7 weeks
Vision of Love - 7 weeks
Love Takes Time - 7 weeks
PAULA (48 weeks/7 = 6.9 weeks)
Rush Rush:
9 Weeks
Cold Hearted: 8 Weeks
Straight Up: 7 Weeks
Opposites Attract: 7 weeks
Forever Your Girl: 6 Weeks
The Way That You Love Me: 6 weeks
The Promise of a New Day: 5 weeks
JANET (79 weeks/13 = 6.1 weeks)
Miss You Much - 8 weeks
Escapade - 8 weeks
Alright - 7 weeks
Love Will Never Do (Without You) - 7 weeks
Rhythm Nation - 6 weeks
What Have You Done For Me Lately - 6 weeks
Nasty - 6 weeks
When I Think of You - 6 weeks
Control - 6 weeks
Let's Wait Awhile - 5 weeks
Come Back to Me - 5 weeks
Black Cat - 5 weeks
Diamonds (Herb Alpert ft. Janet Jackson) - 4 weeks
WHITNEY (85 weeks/14 = 6.1 weeks)
I Wanna Dance With Somebody (Who Loves Me) -
9 weeks
I'm Your Baby Tonight - 8 weeks
I Believe in You and Me - 8 weeks
So Emotional - 8 weeks
Greatest Love of All - 7 weeks
Didn't We Almost Have It All - 7 weeks
All The Man That I Need - 7 weeks
Saving All My Love For You - 7 weeks
You Give Good Love - 6 weeks
How Will I Know - 6 weeks
Where Do Broken Hearts Go - 6 weeks
One Moment In Time - 4 weeks
Love Will Save The Day - 1 week
Miracle - 1 week
MADONNA (115 weeks/22 = 5.2 weeks)
Like a Virgin -
9 weeks
Crazy For You -
9 weeks
Vogue - 8 weeks
Justify My Love - 8 weeks
Papa Don't Preach - 7 weeks
Like a Prayer - 7 weeks
Live to Tell - 6 weeks
Open Your Heart - 6 weeks
Who's That Girl - 6 weeks
Material Girl - 6 weeks
Cherish - 5 weeks
La Isla Bonita - 5 weeks
True Blue - 5 weeks
Lucky Star - 5 weeks
Express Yourself - 5 weeks
Causing a Commotion - 5 weeks
Angel - 4 weeks
Dress You Up - 4 weeks
Keep It Together - 2 weeks
Hanky Panky - 1 week
Rescue Me - 1 week
Borderline - 1 week
CHER (52 weeks/11= 4.7 weeks)
Gypsys, Tramps and Thieves -
9 weeks
Half-Breed - 8 weeks
Dark Lady - 6 weeks
Bang Bang (My Baby Shot Me Down) - 6 weeks
If I Could Turn Back Time - 5 weeks
Just Like Jesse James - 5 weeks
After All (with Peter Cetera) - 4 weeks
The Way of Love - 3 weeks
Take Me Home - 3 weeks
You Better Sit Down Kids - 2 weeks
I Found Someone - 1 week