The Yiddish linguist Max Weinreich published the expression, A shprakh iz a dialekt mit an armey un flot ("אַ שפּראַך איז אַ דיאַלעקט מיט אַן אַרמײ און פֿלאָט"‎: "A language is a dialect with an army and navy") in YIVO Bleter 25. What is illustrated by the frequency by Max Weinreich published his expression?