condition mean min max ZT0-3 2.0797563805 1.481761863 2.6777508979999998 ZT4-7 2.489053141 2.0507329745 2.9273733075 ZT8-11 3.8144835200000005 3.19693577 4.43203127 ZT12-15 4.47693165375 4.1423219795 4.811541328000001 ZT16-19 5.185169933 4.118202869 6.252136997 ZT20-23 9.5232606265 9.309656217 9.736865036000001