condition mean min max ZT0-3 0.833836 0.833836 0.833836 ZT4-7 1.1349550000000002 1.1349550000000002 1.1349550000000002 ZT8-11 1.1963400000000002 1.1963400000000002 1.1963400000000002 ZT12-15 1.251711 1.251711 1.251711 ZT16-19 0.8468733333333333 0.8468733333333333 0.8468733333333333 ZT20-23 1.183645 1.183645 1.183645