Garbage in garbage out. Remember the info is only as good as the info they got. While quite good, the chart is incomplete and should not be seen as totally reliable. For example Air Canada business class is listed as 39-45". That may be true domestically but international seat pitch is 58-65". Same for econo which is 34" international on some planes.
AC business class:
A319, A320: 38"
B737-200: 39"
F28: 41"
A340: 60"
International 767-200: 55"
Domestic 767-200: 45"
B767-300ER: 55-60"
B747-400: 55-65"
DC-9: 38"
AC econo class:
All are 32" with the exception of 34" for the 747s and A340/A330s.