Strange 9a and 9b stats

During 2012, we have seen some 50 guys having done one 9a and the number is increasing every year. At the same time, Adam Ondra is the only one to have done a 9b or more by his 9b+ Change in Flatanger. The first 9b was reported in 1995 ny Fred Rouhling just four years after the first 9a. During the last 16 years, it is actually only Adam Ondra (6 ascents), Chris Sharma (5), Bernabe Fernandez in 2003 and Dani Andrada in 2008 who have done a 9b. Why is it that every year more guys and girls do 9a but the 9b scene is stagnated? The strange thing is that we see the same in bouldering, i.e. the top grade pyramid is just getting wider every year.