2008 to 2009 = -22.5%; 2009 to 2010 = +10.1%; 2010 to 2011 = + 8.1%; 2011 to 2012 = - 4.4%
Net 4 yr decline = -8.7% . Then, the annual dividend trend, affected by production, costs and price of WTI = -2.17% a year lower dividend, excepting a event affecting profit. Based on yesterday's $79.80, theoretically, a year from now the price would be about $78.07 to stay even, with no war effect, no tax change effect, no monetary crisis, ++++
Note, that the price is not rational since BPT was over-priced past year due to chase for yield and failure to accept 'depletion' as an oil well fact. High gravity wells with high flow formations deplete faster. Heavy oil, low API gravity, depletes slower since asphaltic. Tar and asphalt flow slower.
Hope this helps perspective here.