condition mean min max ZT0-3 199.566011 199.566011 199.566011 ZT4-7 194.212539 194.212539 194.212539 ZT8-11 221.47877549999998 221.47877549999998 221.47877549999998 ZT12-15 204.8791725 204.8791725 204.8791725 ZT16-19 223.54450300000002 223.54450300000002 223.54450300000002 ZT20-23 202.18122549999998 202.18122549999998 202.18122549999998