condition mean min max ZT0-3 6.0994275 5.96067 6.238185 ZT4-7 9.003475 9.003475 9.003475 ZT8-11 8.867525 8.867525 8.867525 ZT12-15 0 0 0 ZT16-19 9.555544999999999 9.555544999999999 9.555544999999999 ZT20-23 7.8331800000000005 7.8331800000000005 7.8331800000000005