probably it means the .001% of the avalaible supply of BTC at that time (snapshot).
Actually there are 13,105,025 (coinmarketcap data) so the 0,001% is 131,05. With that amount of btc you would get 190k stellars, and with 0.001 btc you would get 1,45 stellar in this scenario.
Exactly, as I said, per bitcoin you will get about 1500 stellars. The only question is, when are those stellars distributed?