condition mean min max ZT0-3 7.130905 7.130905 7.130905 ZT4-7 9.285255 9.285255 9.285255 ZT8-11 9.158125 9.158125 9.158125 ZT12-15 7.1819749999999996 7.1819749999999996 7.1819749999999996 ZT16-19 9.49364 9.49364 9.49364 ZT20-23 5.6355249999999995 5.6355249999999995 5.6355249999999995