Do you think that the president is really interested in a deal, and is there any real meat in his proposal, do his cuts include ignore the sequester savings as did the Senate budget... so that it would look like they cut 800 billion more than they actually did? Do his cuts include the savings from stopping the wars in Afghanistan and Iraq as did his previous budgets so that he can say he saved money that we were never going to spend in the first place? Let's see what the president really brings to the table before we start grading the republicans.
I doubt that a good course in economics would help you, but a review of investor class as reported by the treasury at the above site might. It doesn't report on China specifically, but does report on purchases by all foreign investors including China. That has gone from an average of $9.8 billion per auction in the 4th quarter of 2009 or 30+% of all purchases to an average of $3.4 billion per auction or less than 14% of the total in the first quarter of 2013.