Another suggestion: update an estimate of words known after every word. E.g. start out with a range of 0 to 170,000. Then after the first word, show 100 to

Another suggestion: update an estimate of words known after every word. E.g. start out with a range of 0 to 170,000. Then after the first word, show 100 to 170,000. Etc. Users get drops of information and can stop whenever they feel. I stopped well before 100.