condition mean min max ZT0-3 2.8297625 2.45112 3.208405 ZT4-7 3.845405 3.845405 3.845405 ZT8-11 1.55571 1.55571 1.55571 ZT12-15 0 0 0 ZT16-19 2.06568 2.06568 2.06568 ZT20-23 3.16149 3.16149 3.16149