condition mean min max ZT0-3 2.48102244475 2.27152848 2.6905164095 ZT4-7 3.9106270292500005 2.900753416 4.9205006425 ZT8-11 7.4704811235 5.830497564 9.110464683 ZT12-15 8.74685540825 7.9744001135 9.519310703 ZT16-19 5.92228888925 5.370317424 6.4742603545 ZT20-23 9.43023624675 8.3443458735 10.516126620000001