Melancholy (Apr 1, 2009)
Sigh (October, 2009) Six months
Boredom (Jul 1, 2010) Nine months
Disappearance (Nov 2, 2010) Four months
Rampage (Jun 7, 2011) Seven months
Wavering (Nov 7, 2011) Five months
Averaging six months (6.2
) and projecting into the future... (Disclaimer: this is a prediction based on the official data above, not official data itself)
VII (Scheme) - Late Spring/Early Summer, 2012
VIII (Anger) - Late Fall, 2012
IX (Dissociation) - Late Spring/Early Summer, 2013
X (Surprise) - Late Fall, 2013
...and possibly X.2 (Surprise pt 2) in 2014.