condition mean min max ZT0-3 0.228812225 0.22749400000000003 0.23013045 ZT4-7 0.3209905 0.3209905 0.3209905 ZT8-11 0.6925749999999999 0.6925749999999999 0.6925749999999999 ZT12-15 0 0 0 ZT16-19 0.29376 0.29376 0.29376 ZT20-23 0.3404435 0.3404435 0.3404435