Hey Neil, if you hold steady at that pace, I'm not sure you have 35 years worth.
Assume a bowl takes an average of 2.5g (20 bowls per tin).
If you smoke 10 bowls per week, that's 25 g per week or 1300g per year.
1300g is 2.866 lbs per year. 55 lbs divided by 2.866 is 19.19 years.
If you want 35 years you should add another 45 lbs.
I know, I'm an enabler.