condition mean min max ZT0-3 10.166783 10.166783 10.166783 ZT4-7 9.8872125 9.8872125 9.8872125 ZT8-11 9.156041 9.156041 9.156041 ZT12-15 10.8493125 10.8493125 10.8493125 ZT16-19 8.96529 8.96529 8.96529 ZT20-23 7.9420955 7.9420955 7.9420955