condition mean min max ZT0-3 4.576305 4.576305 4.576305 ZT4-7 4.727105 4.727105 4.727105 ZT8-11 4.856450000000001 4.856450000000001 4.856450000000001 ZT12-15 7.829705000000001 7.829705000000001 7.829705000000001 ZT16-19 5.379709999999999 5.379709999999999 5.379709999999999 ZT20-23 3.56957 3.56957 3.56957