Hypothosis:
"World of Warcraft players follow the standard model of population distribution."
When looking at the data it is clear that a large portion of subscriptions happened during TBC and Wrath, so going off of this I prepose that the majority of players come from this time.
Standard Model based on current estimate of subscriptions.
Vanillia WOW: SD +2 (~2%) = 140,000 subscriptions
TBC: SD +1 (~14%) = 980,000 subscriptions
Wrath: Median (~68%) = 4,760,000 subscriptions
Cat: SD +1 (~14%) = 980,000 subscriptions
Mop: SD +2 (~2%) = 140,000 subscriptions
Standard Model Weighted to vanilla/TBC players
6% 420,000
16% 1,120,000
65% 4,550,000
12% 840,000
1% 70,000
Standard Model Weighted to Wrath
1% 70,000
12% 840,000
74% 5,180,000
12% 840,000
1% 70,000
Standard Model Weighted to New
1% 70,000
12% 840,000
65% 4,550,000
16% 1,120,000
6% 420,000
Poll included is based on these time periods, so I can create a graph based on what is said to be when you started playing. Please be honest with the poll it will be blind so no one will see when you say you first played.