condition mean min max ZT0-3 7.388555 6.6308 8.14631 ZT4-7 5.571905 5.571905 5.571905 ZT8-11 10.19284 10.19284 10.19284 ZT12-15 0 0 0 ZT16-19 8.12524 8.12524 8.12524 ZT20-23 9.456389999999999 9.456389999999999 9.456389999999999