condition mean min max ZT0-3 1530.396615 1530.396615 1530.396615 ZT4-7 1414.4889705 1414.4889705 1414.4889705 ZT8-11 1085.755758 1085.755758 1085.755758 ZT12-15 1096.9365995 1096.9365995 1096.9365995 ZT16-19 975.6179945 975.6179945 975.6179945 ZT20-23 1172.0224315 1172.0224315 1172.0224315