I took the index on the words, transformed the number to binary, added 3 zeros, calculated the sha256 digest, took the main part of the hexadecimal to convert it to binary, extra 3 zeros to the eight digits from the binary and obtained 00000010011 which translates to 19 in decimal. https://networkbookmarks.com/story19030385/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-definition