condition mean min max ZT0-3 19.08765 18.3512 19.8241 ZT4-7 11.59565 11.59565 11.59565 ZT8-11 12.641 12.641 12.641 ZT12-15 0 0 0 ZT16-19 16.781750000000002 16.781750000000002 16.781750000000002 ZT20-23 14.3224 14.3224 14.3224