condition mean min max ZT0-3 4.010501666666666 3.379235 4.558725 ZT4-7 3.40924 3.40924 3.40924 ZT8-11 3.8524700000000003 3.8524700000000003 3.8524700000000003 ZT12-15 4.4703725 4.3695450000000005 4.5712 ZT16-19 3.8776349999999997 3.8776349999999997 3.8776349999999997 ZT20-23 5.4940549999999995 5.4940549999999995 5.4940549999999995