Take your 20 Overall Top Artists and find how many listeners they have.
The Beatles: 1,679,832
Franz Ferdiand:1,419,615
The Pink Spiders: 66,347
The Fratellis: 591,158
Panic at the Disco: 984,285
Weezer:1,278,269
Alkaline Trio:426,294
Arctic Monkeys:1,083,075
Mindless Self Indulgence:254,165
The Hush Sound:135,582
Saves the Day: 291,155
Danny Elfman:304,244
Sweeney Todd(stephen sondheim):33,644
Blink-182:114,912
My Chemical Romance:906,373
The Hives: 674,343
Steetlight Manifesto: 94,018
Motion City Soundtrack: 378,864
AFI: 656,281
The Blood Brothers: 205,980
Total: 10968662
divided by 20
Average = 548433.10
Divide by the number of listeners the band with the most listeners online has.
Coldplay: 2,168,038
548433/2,168,038 = .2529
x 100= 25.29…