condition mean min max ZT0-3 19.893808 19.893808 19.893808 ZT4-7 24.441322 24.441322 24.441322 ZT8-11 22.369546 22.369546 22.369546 ZT12-15 21.1304845 21.1304845 21.1304845 ZT16-19 22.607234 22.607234 22.607234 ZT20-23 21.82244 21.82244 21.82244