condition mean min max ZT0-3 446.557413 446.557413 446.557413 ZT4-7 361.8997405 361.8997405 361.8997405 ZT8-11 279.1611005 279.1611005 279.1611005 ZT12-15 344.4258825 344.4258825 344.4258825 ZT16-19 227.89180100000002 227.89180100000002 227.89180100000002 ZT20-23 114.79159849999999 114.79159849999999 114.79159849999999