How much up/downtuning can a string survive?

[Stealth]

It all began with watching and listening to too much Michael Manring, then followed onto this thread:

Common tuning change - a hazard to the neck?

Now that I've received some confirmation the neck will hold - here's a question for you string experts.

Assuming a standard set of strings (e.g. a set of Labellas that have been on the bass for a year already) in 45-65-85-105 gauges, how much have you been able to tune them up without breaking the string, or down without losing definition? Obviously, string breakage is a bigger concern because a floppy string is just... well, floppy, not damaged or outright snipped.

[Stealth]

Any input on this, ladies and gentlemen?

[Slats]

I personally find that tuning up and detuning kills strings quicker than anything else. I only change from say a 440 Hz to a 446 Hz as little as possible. I find after X amount of times the strings don't sound quite right, then they don't quite stay in tune....then I realize I need to change strings!

[xgator4u]

up/down tuning is hell on strings, you say they are already a year old... good luck