2017 - Memorial Partakers Worldwide: 19,521. LOL!
w51 1/15 p. 61 par. 17 - "Seeing that we are nearing our complete exodus from this world into the new world, we suggest that all active Kingdom publishers engage in helping the more than half a million attenders out into the field service this coming week end of March 23, 1951. Thus you will aid them in having part in the final witness before the accomplished end of this old world takes place."
Yup, the end was so close 67 years ago that the org urged every visitor to the Memorial to go out on field service. Changed days, eh?