According to these calculations: http://www.reddit.com/r/Bitcoin/comments/1c48u0/how_did_bitcoins_difficulty_stay_at_exactly_1_for/c9cwqn2 http://www.reddit.com

According to these calculations: http://www.reddit.com/r/Bitcoin/comments/1c48u0/how_did_bitcoins_difficulty_stay_at_exactly_1_for/c9cwqn2 http://www.reddit.com/r/Bitcoin/comments/1c48u0/how_did_bitc... The first 1.6 million bitcoins were mined by at most ~15 people.