He also says they invested in 21 companies in the 2004 batch. Which means that 7 other companies returned negligible results.
Average investment per company was about $5mm.
So we can end up with:
$5mm * 115 = $575mm $5mm * 82 = $410mm $5mm * 68 = $340mm $5mm * 30 = $150mm $5mm * 21 = $105mm Total: $1.58B, about $1.5B after losses.
So that comes out toabout a 27% return, using the same math as you, before costs and management fees.