condition mean min max ZT0-3 6.759453 6.759453 6.759453 ZT4-7 7.518720500000001 7.518720500000001 7.518720500000001 ZT8-11 7.695157 7.695157 7.695157 ZT12-15 7.469374 7.469374 7.469374 ZT16-19 7.2108735 7.2108735 7.2108735 ZT20-23 7.408649499999999 7.408649499999999 7.408649499999999