noun
vote counting rate; percentage of votes counted
Used in election reporting to indicate what portion of the total votes has been tallied so far.
開票率が50%を超えた。
The vote counting rate has exceeded 50%.
開票率が上がるにつれて、当選者がはっきりしてきた。
As the percentage of votes counted increased, the winners became clear.
投票率 is voter turnout (percentage of eligible voters who voted), whereas 開票率 is the percentage of cast votes that have been counted.
Compound of 開票 (kaihyō, 'vote counting') and 率 (ritsu, 'rate').