condition mean min max ZT0-3 19.957974999999998 19.22685 20.6891 ZT4-7 16.8052 16.8052 16.8052 ZT8-11 15.0084 15.0084 15.0084 ZT12-15 0 0 0 ZT16-19 26.41285 26.41285 26.41285 ZT20-23 22.21035 22.21035 22.21035