Whilst I appreciate the effort that you have gone through to put together this report, I have no idea where you get the idea that 2011 was the peak of Soi Twilight. If anything it had peaked ten years earlier and was already in its death throes by 2011.
Of course if you look at the statistics it may seem that there were more venues in 2011 than in earlier/later years, but in this case quantity does not equal quality
By 2011 Twilight was already a shadow of its former self and had been abandoned by both its farang and Thai customer base, in this case they were replaced by Chinese tour groups who in the main were there for the shows and not to off boys, party or consume alcohol