Why is the U.S. immigration schedule slowing down in 2011?

In the last few months of 2010, a very significant immigration progress was for applicants holding green card status to apply for their spouses. In December 2010, it even reached a waiting period of only 4 months. This progress has given hope to many spouses of green card applicants. But in January 2011, the schedule for this category was significantly pushed back by two and a half years, to January 1, 2008. The U.S. Department of State stated in the announcement that the number of applications for this type of immigration has increased significantly in the past few months, and it is expected that the number will still be very large, so it seems that this type of applicants should seize the opportunity in the past few months. Application submitted. What I would like to remind everyone here is that if a green card holder applies for a spouse, although the application has been submitted, the green card waiting list has been set back two years due to January. If such applicants submit their applications before January 2011, they will not be approved in the short term.