condition mean min max ZT0-3 9.590577 9.590577 9.590577 ZT4-7 11.8647095 11.8647095 11.8647095 ZT8-11 10.730919 10.730919 10.730919 ZT12-15 8.2331725 8.2331725 8.2331725 ZT16-19 9.355003 9.355003 9.355003 ZT20-23 9.322854 9.322854 9.322854