condition mean min max ZT0-3 13.225375 11.7319 14.71885 ZT4-7 18.02095 18.02095 18.02095 ZT8-11 14.8515 14.8515 14.8515 ZT12-15 0 0 0 ZT16-19 14.5838 14.5838 14.5838 ZT20-23 13.5417 13.5417 13.5417