VizBiz might be showing his age....

I think it was around April/May 2002 that the system changed, as before the amount of TP's you'd earn would depend on route as well as class. I can dig the old earning chart out later if people want to know the exact historics.
Back then I recall it being 70 TP's to hit Gold, and 50 to renew. Silver was silly with something like 10 TP to achieve for 'life' (even thought you didn't) - so one sector in Upper would get you Silver.
But the caveat was that you couldn't earn on Economy flights unless you did three roundtrips in a year, or one premium sector.
A flight in Upper would get you anywhere between 20 and 28 points per return.
A flight in PE would get anything from 6 from 16 points per return.
A flight in Economy would get you anything from 4 points to 8 points.
In Premium or Economy, the points awarded also depends on what you paid for your ticket, whether it was full price or discounted.
Old times gone by - system is overall much better now, but back then if you were doing the NRT or SFO/LAX routes, you could qualify with 3 flights in Upper (not 4 as it is now) and requalify with 2 (not 3 as it is now).
Thanks,
Richard