Jehovah's Witnesses have a presence in most countries in the world. These are the most recent statistics by continent, based on active members, or "publishers" as reported by the Watch Tower Society of Pennsylvania. The Society reports its active presence in various dependencies and states as separate 'lands', as noted.
Bible study figures include studies conducted by Witness parents with their unbaptized children, which can be counted as one hour per week and one Bible study per month, per child.
Other
In addition to the published figures for individual countries, statistics are also published collectively for countries where Jehovah's Witnesses operate covertly under ban, including several Islamic and communist states.
References
Jehovah's Witnesses by country Wikipedia(Text) CC BY-SA