condition mean min max ZT0-3 8.31477 6.62932 10.00022 ZT4-7 8.45065 8.45065 8.45065 ZT8-11 6.94024 6.94024 6.94024 ZT12-15 0 0 0 ZT16-19 8.552610000000001 8.552610000000001 8.552610000000001 ZT20-23 8.66492 8.66492 8.66492