[Quoth]

Also I considered people that speak English and the first language of the country isn't English. I've no idea how many that is.

For Example
India is 7th largest by land mass and now largest population.
English is used extensively in business and administration and has the status of a "subsidiary official language". The literacy rate in 2011 was 74.04%: 65.46% among females and 82.14% among males.[370] The rural-urban literacy gap, which was 21.2 percentage points in 2001, dropped to 16.1 percentage points in 2011. The improvement in the rural literacy rate is twice that of urban areas.[368] Kerala is the most literate state with 93.91% literacy; while Bihar the least with 63.82%.
India has 28 States and 8 Union territories.

Nagaland in India is far North East with pop. of over 2 million. Its official language (and main one in use) is English. It's about 80% Literacy. About 88% are Chrisitans.

Kenya (East Africa) is over 52 Million. Official languages are Swahili and English. Over 85% Christians. British English is primarily used in Kenya. Additionally, a distinct local dialect, Kenyan English, is used by some. There are about 120 ethnic groups and maybe 70 languages. Literacy: total population: 81.5%, male: 85%, female: 78.2%

Botswana, Greek Cyprus, Israel, Netherlands, Scandinavia have high numbers of English speakers.

How many in USA speak Spanish?
How many in USA speak "ethnic" English rather than USA English?


It's more useful to consider people that would easily and regularly use English, which outside of USA and American Colonies isn't American English. Australian and South African English is closer to "British" English. Canada is the only major place with mix, but also has French.

Adult Literacy in the USA is 86%. How many of those have Spanish as first language, or don't speak "White" official USA English? World Average is about 87%

Also interesting is the distribution internationally of sales of English Language books.