Generally yes. The community property percentage should be the time you served while married divided by your total service time(before and during the marriage). And probably most accurate to calculate based on days rather than years.
So pension earned before and after service is your property, pension earned during the marriage is community property to be split between you.
That said, I don't think those formulas are written into law anywhere so you'll need to either come to an agreement with your ex or convince a judge that the percentage you propose is fair. But I'm pretty sure a straight percentage based on service time will usually fly.
If you continue in the service after divorce then I believe that whatever pension you earn after the divorce is yours, and there could be some additional factors if your base pay increases due to longevity or promotion--you could make an argument that your ex's share should only be based on your base pay during the marriage, not your final base pay on which your retirement is based. So that can get complicated.
Also keep in mind that if you have a disability rating less than 50% and are receiving VA disability compensation, that gets deducted from your retired pay. That's an advantage to you since VA disability is not taxable where retired pay is, but it has the effect of reducing your total retired pay and therefor reducing your ex's share.
Edited by TJMH (02/18/16 11:33 PM)