This data period is critical because it is the time when Santa Claus brings goodies to dedicated staff in the way of annual bonuses. Bonuses are not a universal perquisite on the Hill but they are a common way for members to reward staff who have merited them. This assumes that members have budgeted well and have sufficient funds available in their annual allotment, known as the Member's Representational Allowance.
Also controversial is the payment of large bonuses by members of Congress who are departing. With no more concern about getting re-elected, members can be quite generous with taxpayer money toward their staff.
To research your Congressman or Senator's staff salaries, click on http://www.legistorm.com/