condition mean min max ZT0-3 11.373855 11.373855 11.373855 ZT4-7 18.3322225 18.3322225 18.3322225 ZT8-11 14.139106 14.139106 14.139106 ZT12-15 11.909067499999999 11.909067499999999 11.909067499999999 ZT16-19 15.084989 15.084989 15.084989 ZT20-23 13.21951 13.21951 13.21951