condition mean min max ZT0-3 3.1457949999999997 3.1457949999999997 3.1457949999999997 ZT4-7 2.0237800000000004 2.0237800000000004 2.0237800000000004 ZT8-11 1.7358799999999999 1.7358799999999999 1.7358799999999999 ZT12-15 2.152235 2.152235 2.152235 ZT16-19 4.124945 4.124945 4.124945 ZT20-23 3.335045 3.335045 3.335045