condition mean min max ZT0-3 13.279427265750002 4.9068080215 21.65204651 ZT4-7 5.242061230999999 4.0517090504999995 6.4324134115 ZT8-11 7.23863406175 6.0322098655000005 8.445058258 ZT12-15 10.401874192249998 9.513093644 11.290654740499999 ZT16-19 10.41468225225 10.240054755000001 10.5893097495 ZT20-23 10.13042807375 9.6734901475 10.587366