I did some research to back up my claim of 50%.
Sorry but it's worthless to compare the CSeries against older generation aircraft and using short 500nm segments on top of that. The CSeries is competing against new generation aircraft for long-thin segments. And none of the new generation planes from competitors will have per seat mile fuel costs anywhere near that 14.45¢ average from your "other site".
Data from Leeham News (1000nm sectors):
CS300: 1.85 L/100 km
A319Neo: 1.93 L/100 km (+4.3%)
737 MAX-7: 1.94 L/100 km (+4.8%)
E.g. vs. the A319Neo that is less than 4.3% fuel cost per seat mile advantage, and only 5.1% trip fuel cost advantage:
