condition mean min max ZT0-3 15.958516666666666 13.50215 18.9952 ZT4-7 13.97185 13.97185 13.97185 ZT8-11 12.9266 12.9266 12.9266 ZT12-15 23.383275 20.37825 26.3883 ZT16-19 27.530450000000002 27.530450000000002 27.530450000000002 ZT20-23 24.58765 24.58765 24.58765