condition mean min max ZT0-3 0.994486 0.66443 1.435395 ZT4-7 1.217611 1.217611 1.217611 ZT8-11 0.9031530000000001 0.9031530000000001 0.9031530000000001 ZT12-15 1.6892125 1.375155 2.00327 ZT16-19 1.42097 1.42097 1.42097 ZT20-23 2.243555 2.243555 2.243555