condition mean min max ZT0-3 3.8686593492499997 3.5056727515 4.231645947 ZT4-7 2.26367664125 1.7267271455 2.800626137 ZT8-11 4.174986083249999 3.1932964745 5.156675691999999 ZT12-15 9.26427530825 7.566580356999999 10.961970259500001 ZT16-19 6.2859009325 5.676891148999999 6.894910716 ZT20-23 10.921566232 9.229566204000001 12.613566259999999