About 54% of them reported earning less than $50,000 annually, compared with 39% of the other participants.
In addition to his Congressional salary, he reported earning $20,000 from the church.
The family reported earning $209,011 last year, meaning that their total income rose 28 percent.
Last week, Church & Dwight reported earning $6.1 million, a 75 percent decline from 1993.
Nabors reported earning $428.4 million in profits in the United States last year.
The firm reported earning $27.4 million in lobbying fees in 2011.
That is a 37 percent drop from 1998, when she and her husband John, who manages an investment account, reported earning $1.86 million.
The higher-paid ones reported earning less than they really do, to bring themselves down to the norm.
He reported earning $149,545 in salary and $164,125 from pensions.
That is down from last year, when she reported earning $2.3 million in royalties from her memoir.