condition mean min max ZT0-3 5.83712 5.83712 5.83712 ZT4-7 6.5829450000000005 6.5829450000000005 6.5829450000000005 ZT8-11 4.8947 4.8947 4.8947 ZT12-15 4.435734999999999 4.435734999999999 4.435734999999999 ZT16-19 3.77739 3.77739 3.77739 ZT20-23 3.957675 3.957675 3.957675