condition mean min max ZT0-3 30.274689 30.274689 30.274689 ZT4-7 31.9760415 31.9760415 31.9760415 ZT8-11 32.5704125 32.5704125 32.5704125 ZT12-15 31.0820175 31.0820175 31.0820175 ZT16-19 44.606983 44.606983 44.606983 ZT20-23 42.175854 42.175854 42.175854