add the album sales and divide them by the number of albums.
ONLY use official albums not remix albums or greatest hits albums.
Shakira: 5m + 7m + 16m + 4m + 8m + 2m + 4m + 1m = 47m albums
47m divided by 8 = 5.875 million albums.
so Shakira's average album sales is : 5.875 million albums! WOW!
NEW: you can now do singles sales if you have the time lol
any single which has sold less then 1 million copies WW can be ignored from your calculations.