condition mean min max ZT0-3 7.52662 5.3390450000000005 8.89375 ZT4-7 6.84351 6.84351 6.84351 ZT8-11 5.8195049999999995 5.8195049999999995 5.8195049999999995 ZT12-15 7.794387499999999 7.7017999999999995 7.886975 ZT16-19 7.212155 7.212155 7.212155 ZT20-23 9.60947 9.60947 9.60947