condition mean min max ZT0-3 1.52025461125 1.2984417495 1.742067473 ZT4-7 2.26842011825 2.1041889019999998 2.4326513345 ZT8-11 2.1451319897500003 1.9654555980000001 2.3248083815 ZT12-15 6.958431976750001 5.225902509 8.690961444500001 ZT16-19 10.2625968675 9.7175313905 10.807662344499999 ZT20-23 11.2790884325 10.876521795 11.68165507