condition mean min max ZT0-3 0.7985267600000001 0.341093883 1.2559596370000001 ZT4-7 3.4124786512500003 2.716046349 4.108910953500001 ZT8-11 4.100514041 3.832141514 4.368886568 ZT12-15 9.714844244 7.5424264435 11.8872620445 ZT16-19 12.674662725 11.363470985 13.985854465 ZT20-23 21.5468913325 19.374970655 23.71881201