condition mean min max ZT0-3 349.162062 349.162062 349.162062 ZT4-7 397.6787915 397.6787915 397.6787915 ZT8-11 406.46028049999995 406.46028049999995 406.46028049999995 ZT12-15 407.450441 407.450441 407.450441 ZT16-19 339.762328 339.762328 339.762328 ZT20-23 264.36213050000003 264.36213050000003 264.36213050000003