It would be very interesting to see those figures normalised to a constant data rate / bandwidth.  For example, PSK31 shown at -10dB is identical to PKK63 at -7dB - well it would be, its the same modulation, just faster.   Ie plot Bits/second/Hz vs. Eb/No, then stick the Shannon limit on the graph and see which lie nearest.

 

The fact that JT65 is at the top is probably because it sits at around 0.27 chars / second, or something like 1.2 B/s.  Although even after normalisation, it would no doubt still score well up.

 

Andy
www.g4jnt.com