condition mean min max ZT0-3 5.620165 5.620165 5.620165 ZT4-7 4.258215 4.258215 4.258215 ZT8-11 7.3997 7.3997 7.3997 ZT12-15 10.8368 10.8368 10.8368 ZT16-19 9.637595000000001 9.637595000000001 9.637595000000001 ZT20-23 6.849865 6.849865 6.849865