You got trusted contributor because you give enough information and people rated your posts as useful.
May be because you ask the questions people didn't dare asking but always wanted to know.
The status is "volatile". With only 3 ratings you currently have an average of 4 out of 5.
One rating below 4 will change your average below 4 and will not be Trusted.
It come and goes depending on the participation, I like it.
Every post, so every individual can be rated.
I have to say I like this system, so you can highlight appreciated participation and also see members with less helpful behaviour.
If you wish, you can open a thread in the Forum Use, Policies, and General Questions
on the subject. You will be able to see there are different opinions.