"Some", 17% is a bit more than "some".
Baseman explain to me why the mixed population increased by 70% between 1991 and 2012. Note that any one born in 1992 was 23 in 2014.
Waiting your answer. Because this will determine what you think that the ethnic composition of the voting age population is, relative to those too young to vote.
My Arithmatic is based on the larger picture. The two main groups (Indian/Afro) constitute 75% of the total population. So it's 25% up for grabs. PPP seem to have grabbed 50% of these, even by your own WAG.
I suggest you adjust your arithmetic. APNU AFC got 51% of the votes when the African population is 30%.
You are using the 2002 numbers to assume what the ethnic vote is. So PPP
is 39% Indian, 7% Amerindian, meaning 1% African and 2% mixed.
APNU AFC will be 29% African, 3% Amerindian, 4% Indians meaning 15% mixed. That is basically all of the mixed vote, using your 2002 numbers. APNU AFC captured almost 90% of the mixed vote.