jm ¡ý ¸w~Z°KðºYLÌ%^y/«þ§"¤ËgGLMy assumption is that most of the transactions are being generated directly at the miners and therefore don't have to propagate. I have no proof though.
https://whatsonchain.com/tx/d7b631cbbb6753359a2168ddce21326b109060f05097ee0b43afdf635c60d41b