Rihanna started in 2005…
In 2005 Rihanna signed a record deal with Def Jam Recordings to launch her career. Rihanna has sold more than 25 million albums and 60 million singles worldwide since the beginning of her career, which makes her one of the best selling artists of all time. She has released four Recording Industry Association of America certified platinum and multi-platinum albums in the United States.
http://acharts.us/performer/rihanna
Rihanna has attained eleven number-one songs on the Billboard Hot 100, making her just the seventh artist to earn this plateau in the 53-year history of the chart.[2] Billboard named Rihanna the Digital Songs Artist of the 2000s decade, and ranked her as the seventeenth artist of the same decade.