When you analyse this, you will note that members of Congress are politicians and, by default, politicians don't acutally work. To do so, you would have to earn the money you make. So my answer is zero for all politicans, not just Congress. People who actually work provide something useful such as goods or services that the consumer can actually use and those products must be competitively priced to be viable. Congress, and other political bodies, have a reputation for sanctioning purchases that are highly overpriced and self-serving for their jurisdictions.
I honestly don't know the answer that you are looking for but I feel it matters little since the political networks have shown that they have outlived their original usefulness and another "system" needs to replace it, but we know that Congress wouldn't allow that to happen. Who would actually hire these people?