condition mean min max ZT0-3 336.2511943 273.6171355 398.8852531 ZT4-7 244.200511025 210.93411475 277.4669073 ZT8-11 92.29600568749999 79.459040035 105.13297133999998 ZT12-15 68.308101 66.603077265 70.01312473499999 ZT16-19 95.6531495075 90.97591025 100.33038876500001 ZT20-23 89.018952195 76.25656019 101.78134419999999