condition mean min max ZT0-3 13.844453 13.844453 13.844453 ZT4-7 14.664612 14.664612 14.664612 ZT8-11 12.0543185 12.0543185 12.0543185 ZT12-15 11.8357455 11.8357455 11.8357455 ZT16-19 11.113636 11.113636 11.113636 ZT20-23 12.619251 12.619251 12.619251