Table 5.

The top three statistically significant regressions with the highest $R_{\text{adj}}^2$ for a given number of predictors. The coefficients correspond to a linear model of the form log(N_d) = a₀ + Σa_i log(P_i).

	Predictors (Pi) and their respective coefficients (ai)
No. of Predictors	a0	a1	P1	a2	P2	a3	P3	a4	P4	a5	P5	$R_{\text{adj}}^2$
1	2.05	0.32	${\text{Tot-SO}}_4^{2-}$									0.40
	2.33	0.25	${\text{NH}}_4^{+}$									0.34
	2.13	0.28	${\text{NSS-SO}}_4^{2-}$									0.29
2	2.18	0.22	${\text{Tot-SO}}_4^{2-}$	0.12	${\text{NH}}_4^{+}$							0.48
	2.43	0.21	MSA	0.15	${\text{NH}}_4^{+}$							0.44
	2.25	0.19	${\text{NH}}_4^{+}$	0.09	Na							0.42
3	2.25	0.13	${\text{NSS-SO}}_4^{2-}$	0.13	${\text{NH}}_4^{+}$	0.10	Na					0.50
	2.24	0.19	${\text{Tot-SO}}_4^{2-}$	0.10	Ox	0.07	${\text{NH}}_4^{+}$					0.49
	2.25	0.17	${\text{Tot-SO}}_4^{2-}$	0.11	${\text{NH}}_4^{+}$	0.08	MSA					0.49
4	2.32	0.21	${\text{Tot-SO}}_4^{2-}$	0.20	Ox	0.09	${\text{NH}}_4^{+}$	−0.15	${\text{NO}}_3^{-}$			0.52
	2.29	0.11	${\text{NSS-SO}}_4^{2-}$	0.10	Ox	0.09	Na	0.08	${\text{NH}}_4^{+}$			0.51
	2.31	0.11	${\text{NH}}_4^{+}$	0.10	NSS	0.10	MSA	0.08	Na			0.51
5	2.10	0.13	Na	0.12	Ox	0.11	${\text{NSS-SO}}_4^{2-}$	0.08	${\text{NH}}_4^{+}$	−0.05	V	0.56
	2.40	0.23	Ox	0.13	${\text{NSS-SO}}_4^{2-}$	0.10	${\text{NH}}_4^{+}$	0.09	Na	−0.17	${\text{NO}}_3^{-}$	0.55
	2.36	0.14	${\text{NH}}_4^{+}$	0.14	MSA	0.12	${\text{NSS-SO}}_4^{2-}$	0.07	Na	−0.08	${\text{NO}}_3^{-}$	0.52