I took the index of the words, transformed the number to binary, additional three zeros, calculated the sha256 digest, took the primary part of the hexadecimal to transform it to binary, added 3 zeros to your 8 digits of your binary and received 00000010011 which translates to 19 in decimal. https://kingslists.com/story20207766/5-essential-elements-for-bip39-explained