hi guys

can anyone tell me how capital gains tax is worked out with regard to RTD?
I have held shares for 3 whole years and made around 12K gain over 8800 CGT. I know RTD was in small caps index and techmark 100 index.
What tax do i need to pay?..........hows it worked out.
Oh, i am not a top rate taxpayer, just normal tax payer in the year.

any calcs to help will be appreciated

Ok, apologies if I'm wrong, thats the way I understood it, but I don't claim to be an expert.