My question involves labor and employment law for the state of: CA

These questions probably have been answered on this site already. Anyways, here goes:

Background:
I have been receiving a partial UI benefit every week for almost a year, because I work less than 40 hours per week, and my income at my current job is low enough suh that I still receive a little each week in addition to my current job wages.

My questions are about UI claim audits.
1) Does the EDD conduct an audit on every UI claim?
2) If so, is it done: daily, weekly, quarterly, yearly...?
3) Do they look at what the employer reports, or what the employee reports?
4) Referring to 3) above ^^ ... Or both, as in a "comparison" between the two?