The globes are filled with high pressure gas. Over time the gas seeps through the membrane and into the fluid and eventually out of the system.
This process is like a balloon going flat, but it takes 8-10 years. *** estimated
Maybe changing the fluid more can slow it down, but physics is physics.
I highly doubt any 2008 to 2011 models on original globes are still at factory 100% function.
The hardest part of my globe changing experience was getting the stock sliders off the car. You can and should do this one at home.