The poll options are pretty ill-chosen, considering that, as pointed out, it's almost impossible to have more than 50%.
Tweed does. Although as verin noted you could not count him for about a year or so.
Not quite. Even counting his tenure as continuous, he was just under 13 when he joined the (old) forum, and he's now 23 (he was born c. December 1990, if memory serves), so his percentage would be approximately 48.5% at best.
I was born 10/27/1990, I registered on the old board on 05/23/2003. so I was approx. 12.57 years old when I registered. today I am approx. 23.74. putting me almost exactly on the 47% dot. I won't cross into 50% until December 2015, assuming you want to count me as continuous, as you noted.