condition mean min max ZT0-3 1.8316824999999999 1.49658 2.166785 ZT4-7 2.196535 2.196535 2.196535 ZT8-11 2.641445 2.641445 2.641445 ZT12-15 0 0 0 ZT16-19 2.985075 2.985075 2.985075 ZT20-23 2.259455 2.259455 2.259455