condition mean min max ZT0-3 7.8733 7.8733 7.8733 ZT4-7 5.13645 5.13645 5.13645 ZT8-11 5.88481 5.88481 5.88481 ZT12-15 6.05907 6.05907 6.05907 ZT16-19 10.71416 10.71416 10.71416 ZT20-23 9.183150000000001 9.183150000000001 9.183150000000001