condition mean min max ZT0-3 3.0869725 2.98251 3.191435 ZT4-7 2.6751300000000002 2.6751300000000002 2.6751300000000002 ZT8-11 4.043794999999999 4.043794999999999 4.043794999999999 ZT12-15 0 0 0 ZT16-19 3.7135499999999997 3.7135499999999997 3.7135499999999997 ZT20-23 4.097975 4.097975 4.097975