NO.PZ2020033002000023
问题如下：
A table provided by a rating company shows that the number of A-rated issuers that moved to AAA is 1, the number that moved to AA was 6, the number that stayed at A was 41, the number that moved to BBB was 2 and the number that went into default was 3. Based on the above information, let's say there is a new company with an A credit rating, what is the probability that it will be downgraded or defaulted after one year?
选项：
A. 3.77%
B. 5.67%
C. 1.89%
D. 13.21%
解释：
B is correct.
考点：Credit Transition Matrices
解析：降级或者违约的概率=（2+3）/（1+6+41+2+3）=5.67%
5除以53怎么会是这个答案呢
