condition mean min max ZT0-3 18.3700319525 18.363291405 18.376772499999998 ZT4-7 21.140452575 20.21387083 22.06703432 ZT8-11 21.836770385 21.228844776666666 22.444695993333333 ZT12-15 18.271384535000003 17.441569683333334 19.101199386666668 ZT16-19 17.03670358666667 16.49878396333333 17.574623210000002 ZT20-23 17.880149109999998 17.63151692 18.1287813