Using multiple IF statements in Excel Base off of three critieria

I am trying to build a nested If statement I have three columns they are either going to say "yes" or "no" I need to write a If statement that gives me the below

If all three columns have "yes" then I want to return 100%
If only two yes and one no in all three columns then I want to return 66.6%
If only one yes and the rest no I want to return 33.3%

Basically

1 yes = 33.3%
2 yes= 66.6%
3 yes = 100%
or if all three columns have a No then it would be 0%

I am not sure if I am doing this correct this is the formula I'm trying and keep getting an error forgive me but I am not up to par with If statements

IF((BC5="YES",BD5="YES",BE5="NO"),66.6%,IF(BC5="YES",BD"NO",BE5="NO"),33.3%,IF(BC5="YES",BD"YES",BE5="YES"):,"100%,0%)))


Any help would be apprecaited