condition mean min max ZT0-3 4.230405 4.230405 4.230405 ZT4-7 3.022065 3.022065 3.022065 ZT8-11 3.50346 3.50346 3.50346 ZT12-15 3.923835 3.923835 3.923835 ZT16-19 5.625109999999999 5.625109999999999 5.625109999999999 ZT20-23 4.95415 4.95415 4.95415