condition mean min max ZT0-3 234.935083 234.935083 234.935083 ZT4-7 189.4054845 189.4054845 189.4054845 ZT8-11 180.821708 180.821708 180.821708 ZT12-15 222.6174575 222.6174575 222.6174575 ZT16-19 233.1398415 233.1398415 233.1398415 ZT20-23 232.6188255 232.6188255 232.6188255