So which is it, if a spouse is married to a 100% P&T veteran, how many years does she have to be married to him/her to qualify for the highe?

So which is it, if a spouse is married to a 100% P&T veteran, how many years does she have to be married to him/her to qualify for the higher rate of DIC? 8 years or 10 years and why since there are two different dates on the DIC web site and under the CFR the two years are listed.