"The latest worldwide service report (for 2012) shows that there was roughly 300,000 fewer in attendance at the memorial worldwide than there were in 2011 "
I wouldn't pay too much attention to that (unless it keeps on dropping .........), the number has always been fluctuating according to what day the Memorial was celebrated. If during the Easter holidays, more people will be on vacation / trips, but if at the very beginning of the Easter week, more people will be at home and attend. 2012, April 5th was a holiday in large parts of the world. 2011, April 17th was BEFORE the Easter week. You would therefore expect a number of half siblings not attending. This year, March 26th will be in the Easter week but before the holidays for large parts of the world. More comparable to 2011.