Asparagus harvesting question

[Gman]

This is the 3rd year my asparagus crowns have been in the ground.
I understand that this means I can now pick some for the 1st few weeks of spears coming up, and then stop.
I notice that I have some spears of decent girth (maybe like a finger) and have harvested these. There are also a few that are really skinny (like a matchstick) and everything in between.
Do I harvest all of them, fat and skinny for 4 weeks or so and then let everything grow? Or do I just harvest the big ones and leave the others behind? But I doubt the skinny ones will survive even the slightest gust once the Fermí bits open up.
G

[mrbadexample]

I'm in the same position - 3rd year and starting to get some nice thick spears. I've harvested 6 of the biggest, but I don't think I'll take much more this year. I'll leave the smaller ones.