if you have a poll with 2 options (say yes and no) and 2 voters vote no and 1 yes, it will show 33% yes and 66% no, which should be 33% yes and 67% no

Unless I'm looking at this wrong,
$option_pct_txt = sprintf("%.1d%%", ($option_pct * 100));

should be:
$option_pct_txt = sprintf("%.1d%%", round($option_pct * 100));