What you've been given there is a gear compatability chart (i.e. what gears will actually a fit), rather than a gear ratio chart.
Your TC comes with a 78 spur, right? the other figure you need to know is the internal ratio of 2.2:1
So, from the gear ratio formula (which I'm sure someone has posted for you before)....
6 = (78 spur/? pinion)x2.2
or ? pinion = (78x2.2)/6 = 28.6
So a 28 or 29 pinion will give roughly the ratio you want.