condition mean min max ZT0-3 1.8920715 1.0896295 3.168415 ZT4-7 0.6283464999999999 0.6283464999999999 0.6283464999999999 ZT8-11 0.872565 0.872565 0.872565 ZT12-15 3.3467725 2.80997 3.883575 ZT16-19 2.335355 2.335355 2.335355 ZT20-23 3.69245 3.69245 3.69245