condition mean min max ZT0-3 9.265397499999999 9.115905 9.41489 ZT4-7 7.0204249999999995 7.0204249999999995 7.0204249999999995 ZT8-11 6.917109999999999 6.917109999999999 6.917109999999999 ZT12-15 0 0 0 ZT16-19 9.29129 9.29129 9.29129 ZT20-23 10.3259 10.3259 10.3259