How often to you change your razor blade

Family, Education, Health and Pets
1
Inspired by the wet shaving thread .

How often to you change your razor blade?

2
at least once a year for me.

3
what about a entry for the electric shavers, for balance ?

4
I can only use Gillette Fusion Pro Glides (super expensive here, I get them from the US in huge packs from Costco). I am pretty religious at 3 weeks. The pro glide gives me such a good shave, I only have to shave every other day. If I shaved daily, I would be on a fortnight rotation.

5

Just an estimate, but maybe every 30 years?