condition mean min max ZT0-3 10.647725 10.647725 10.647725 ZT4-7 8.177056 8.177056 8.177056 ZT8-11 8.6329755 8.6329755 8.6329755 ZT12-15 8.231137 8.231137 8.231137 ZT16-19 7.434278000000001 7.434278000000001 7.434278000000001 ZT20-23 7.838665499999999 7.838665499999999 7.838665499999999