This is a question I get a lot.
And here's the answer:
Numbers of kendo grade holders, as at January 2003
初段 634,678 (shodan)
二段 385,890 (nidan)
三段 162,061 (sandan)
四段 41,463 (yondan)
五段 38,573 (godan)
六段 14,011 (rokudan)
七段 11,877 (nanadan)
八段 466 (hachidan)
九段 13 (kyū-dan-9th Dan) only 4 still active: Inoue sensei, Okuzono sensei, Taniguchi sensei and Kurasawa sensei.
全国登録計 1,288,033 (All Japan Total) (women 28%)
錬士 19,258 (Renshi)
教士 18,000 (Kyoshi)
範士 376 (Hanshi)
There had been only five 10th dan in kendo history. From 1995 the grades 9th and 10th cannot be awarded. The total 9th dan ever awarded seems to be about twenty.
And then, by Curtis Marsten sensei's reckoning, it takes more than 86,000 people to pass 6 and 7 dan for there to be just ten new 8 dans!
(Note: these figures are only for Japan. Thanks to Raffa at Kendo World for this info). b