EDIT:
After writing this, I was curious how the BLS calculates wages. Here is the answer from their FAQ: http://www.bls.gov/oes/oes_ques.htm#overview
The following are excluded from the collection of OES wage data:
Attendance bonuses
Back pay
Clothing allowances
Discount
Draw
Holiday bonus
Holiday premium pay
Jury duty pay
Meal and lodging payments
Merchandise discounts
Non-production bonuses
On-call pay
Overtime pay
Perquisites
Profit-sharing payments
Relocation allowances
Severance pay
Shift differentials
Stock bonuses
Tool/equipment allowances
Tuition repayment
Uniform allowance
Weekend premium pay
Year-end bonuses
This means that BLS data is basically garbage for software engineers. And it's somewhat harmful, because companies probably use this trusted government data to check market rates. Even if a company has good intentions and wants to pay market rate, if they use this data they won't realize just how little that is compared to the true market rate.