condition mean min max ZT0-3 6.67749 5.536384999999999 7.818595 ZT4-7 7.53045 7.53045 7.53045 ZT8-11 15.9543 15.9543 15.9543 ZT12-15 0 0 0 ZT16-19 13.58315 13.58315 13.58315 ZT20-23 10.36035 10.36035 10.36035