I dont do my taxes for a while so I dont know exactly what expenses were but I do know what my revenues were. 2011 was 5% higher than 2010 but 2.5% lower than 2009. My business expenses are likely pretty comparable across all those years. Healthcare was up last year. Bought a car last year so depreciation will pull down taxable income too. All things considered my income has been remarkably consistent the last several years for someone on straight commission.
BTW that bonus you get in April is 2012 earnings even though it was for performance last year. For those of us on commission the lag in pay for performance could be even longer than yours. I end up getting paid 6 to 12 months after starting with most clients. With short sales it can be even longer.