Table 2 Correlations among standard machine yields and physical parameters across countries

	Ventilation	Cigarette PD	Cigarette diameter	Rod length	Filter length	Tipping length	Tobacco weight	Filter weight	Rod density	Filter density	Filter PD
Tar	−0.93*	0.60*	−0.01	−0.63*	0.39*	0.51*	−0.46*	−0.42*	0.42*	−0.06	−0.71*
Nicotine	−0.87*	0.61*	0.12	−0.67*	0.47*	0.58*	−0.48*	−0.44*	0.41*	−0.11	−0.67*
CO	−0.94*	0.65*	−0.01	−0.59*	0.35*	0.45*	−0.41*	−0.42*	0.37*	−0.1	−0.66*
Ventilation (%)	1	−0.69*	0	−0.33*	0.40*	0.56*	−0.40*	0.41*	−0.32*	0.11	0.69*
Cigarette PD (mm H₂O)		1	−0.07	0.23*	−0.30*	−0.37*	0.44*	−0.14	0.44*	0.20*	−0.12
Cigarette diameter (mm)			1	0.24*	−0.15	−0.15**	0.21*	−0.17**	−0.35*	−0.56*	−0.17**
Tobacco rod length (mm)				1	−0.87*	−0.82*	0.65*	−0.75*	0.15	−0.14	−0.60*
Filter length (mm)					1	0.83*	−0.64*	0.77*	−0.25*	−0.03	0.57*
Tipping length (mm)						1	−0.60*	0.72*	−0.22*	0.14	0.63*
Tobacco rod weight (g)							1	−0.43*	0.76*	0.07	−0.44*
Filter weight (g)								1	−0.06*	0.44*	0.67*
Rod density (mg/cm³)									1	0.42*	−0.16**
Filter density (mg/cm³)										1	0.36*

PD, pressure drop.
*p<0.01, **p<0.05.