Figures on Green


Top o’ the mornin’.

I’m writing an article on the Green altitude and would like to quote some reliable percentages of Green. Estimates for percentage of Green people in high-income countries is my priority, but worldwide estimates would also be handy. I often hear numbers like 20-25% in the States and a slightly higher percentage in Northern Europe but I’ve no idea where these figures come from.

I’m also interested in when Green becomes available to people nowadays in high-income societies. My hunch is late adolescence for certain socioeconomic groups, like university students, but I have no convincing evidence for that.

Can anybody suggest any reliable figures or point me to research on this?

Any help is much appreciated.