condition mean min max ZT0-3 3.2395400000000003 3.2395400000000003 3.2395400000000003 ZT4-7 3.193205 3.193205 3.193205 ZT8-11 1.86124 1.86124 1.86124 ZT12-15 2.1244050000000003 2.1244050000000003 2.1244050000000003 ZT16-19 2.72123 2.72123 2.72123 ZT20-23 3.6785933333333336 3.6785933333333336 3.6785933333333336