condition mean min max ZT0-3 2.56261595175 2.140196915 2.9850349885 ZT4-7 4.717988158 2.7267347770000003 6.709241539 ZT8-11 45.3544370475 24.246280595 66.4625935 ZT12-15 67.27929429 53.15046835 81.40812023 ZT16-19 26.566591295000002 22.424605765000003 30.708576824999998 ZT20-23 14.161906137499999 11.72282645 16.600985825