I took the index of your words, transformed the number to binary, extra a few zeros, calculated the sha256 digest, took the 1st Section of the hexadecimal to convert it to binary, extra three zeros for the 8 digits on the binary and obtained 00000010011 which translates to 19 in https://health-lists.com/story19583452/the-greatest-guide-to-seed-phrase-bip39