condition mean min max ZT0-3 242.382787 242.382787 242.382787 ZT4-7 244.7052865 244.7052865 244.7052865 ZT8-11 225.5479025 225.5479025 225.5479025 ZT12-15 244.083505 244.083505 244.083505 ZT16-19 282.9669675 282.9669675 282.9669675 ZT20-23 349.224985 349.224985 349.224985