From Nxt BCE, we get that there are only 581 accounts as block 8303, which means there are only 581 accounts have some coins. So maybe not more than 500 people all around the world own Nxt.
Keep on trading, keep on distributing to get Pareto Optimality.
A lot of those accounts are very low balance as well. My balance of 334 will only net me 1 block a year, statistically.