condition mean min max ZT0-3 3.08512 1.945955 5.34099 ZT4-7 2.6947400000000004 2.6947400000000004 2.6947400000000004 ZT8-11 2.87315 2.87315 2.87315 ZT12-15 8.5842525 7.868575 9.29993 ZT16-19 5.77007 5.77007 5.77007 ZT20-23 4.003349999999999 4.003349999999999 4.003349999999999