condition mean min max ZT0-3 7.998541 7.998541 7.998541 ZT4-7 9.1925745 9.1925745 9.1925745 ZT8-11 8.279316 8.279316 8.279316 ZT12-15 8.001682 8.001682 8.001682 ZT16-19 8.8782975 8.8782975 8.8782975 ZT20-23 10.012784 10.012784 10.012784