condition mean min max ZT0-3 11.03745 11.03745 11.03745 ZT4-7 8.20538 8.20538 8.20538 ZT8-11 9.076080000000001 9.076080000000001 9.076080000000001 ZT12-15 8.894055000000002 8.894055000000002 8.894055000000002 ZT16-19 13.518550000000001 13.518550000000001 13.518550000000001 ZT20-23 13.54475 13.54475 13.54475