condition mean min max ZT0-3 38.093100505 31.02508602 45.16111499 ZT4-7 3.135166547 2.013427759 4.256905335 ZT8-11 7.19097971725 4.285774312 10.0961851225 ZT12-15 7.239925728999999 6.787252381 7.692599077 ZT16-19 16.059948776 9.908621317 22.211276235 ZT20-23 32.4040462925 29.919256675 34.88883591