condition mean min max ZT0-3 16.84565 16.84565 16.84565 ZT4-7 13.99895 13.99895 13.99895 ZT8-11 16.1109 16.1109 16.1109 ZT12-15 20.52915 20.52915 20.52915 ZT16-19 17.76285 17.76285 17.76285 ZT20-23 16.0685 16.0685 16.0685