Janet Jackson :
Debuted in : 1982
Last #1 : All For You (2001)
Last solo/lead #1 : All for You
1982 - 2001 = 19 years into her career
Last TOP10 :Someone To Call My Lover #3(2001)
1982 - 2001 = 19 years into her career

Madonna :
Debuted in : 1983
Last #1 : Music (2000)
Last solo #1 : Music
1983 - 2000 = 17 years into her career
Last TOP10 :Give Me All Your Luvin' #10 (2012)
1983 - 2012 = 29 years into her career

Kylie Minogue :
Debuted in : 1988
Last #1 : Not found
Highest charting song : The Loco-Motion #3 (1988)
Last Top10 :Can't Get You Out Of My Head #7 (2002)
1988 - 2002 = 14 years into her career