condition mean min max ZT0-3 1.379648 1.379648 1.379648 ZT4-7 0.7144245 0.7144245 0.7144245 ZT8-11 1.0187975 1.0187975 1.0187975 ZT12-15 1.426985 1.426985 1.426985 ZT16-19 1.78089 1.78089 1.78089 ZT20-23 1.26538 1.26538 1.26538