condition mean min max ZT0-3 1466.627895 1466.627895 1466.627895 ZT4-7 659.8564005000001 659.8564005000001 659.8564005000001 ZT8-11 917.7966449999999 917.7966449999999 917.7966449999999 ZT12-15 1144.6935950000002 1144.6935950000002 1144.6935950000002 ZT16-19 1359.4722625 1359.4722625 1359.4722625 ZT20-23 1375.5299115 1375.5299115 1375.5299115