I took the index from the words, converted the range to binary, added three zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, added 3 zeros to your eight digits of the binary and received 00000010011 which translates to 19 in decimal. https://dftsocial.com/story19635973/little-known-facts-about-bip39-seed-phrase-list