Points to Note
Whether two ratings are statistically distinguishable depends on the value of their difference and the standard errors of their scores. Generally speaking, at 95% confidence level, a difference of over two standard errors can be taken as meaningful.
Whether a legislator or political group is on the list or not is sometimes marginally determined by one's recognition rate. Higher recognition rate means more people know of the person or group, and can be taken as the first benchmark in comparing popularity. Support rating is the second, and the two are not necessarily related. If the recognition rate of a person or group is only marginal, one could top the list this time, but drop out completely next time.
Before June 1999, the popularity of political groups were gauged by the "top five" method. After that, they are measured by "top ten" method. ASPDMC was admitted as a political group after June 1999.