Average member age	Male percentage	Household size	Household income	Adult percentage	No high school percentage	Bachelor’s degree percentage	Number of vehicles	Home ownership	Number of trips per day	Travel time per day	Gas price	Shopping trip percentage	Urban area	Population density	Daily Internet use
2009
Average member age	1.00
Male percentage	− 0.01	1.00
Household size	− 0.54	0.06	1.00
Household income	− 0.13	0.13	0.19	1.00
Adult percentage	0.51	0.02	− 0.77	− 0.13	1.00
No high school percentage	− 0.06	0.01	0.07	− 0.17	− 0.03	1.00
Bachelor’s degree percentage	− 0.05	0.04	0.02	0.20	− 0.07	− 0.11	1.00
Number of vehicles	− 0.20	0.10	0.34	0.30	− 0.08	− 0.02	− 0.01	1.00
Home ownership	0.15	0.01	0.02	0.25	0.06	− 0.09	0.05	0.22	1.00
Number of trips per day	− 0.16	0.07	0.28	0.24	− 0.15	− 0.03	0.07	0.22	0.07	1.00
Travel time per day	0.00	0.03	− 0.01	0.03	0.03	0.00	− 0.01	0.04	0.00	− 0.14	1.00
Gas price	− 0.01	0.00	0.00	− 0.01	0.01	0.00	− 0.02	0.00	− 0.01	0.01	0.01	1.00
Shopping trip percentage	0.17	0.03	− 0.13	− 0.10	0.15	0.01	− 0.02	− 0.06	− 0.01	− 0.07	− 0.13	0.00	1.00
Urban area	− 0.03	0.01	− 0.02	− 0.03	0.01	0.01	0.01	− 0.13	− 0.14	− 0.01	− 0.01	0.01	0.01	1.00
Population density	− 0.05	0.01	− 0.02	− 0.02	0.01	0.01	0.02	− 0.19	− 0.21	− 0.01	− 0.01	0.01	0.01	0.63	1.00
Daily Internet use	− 0.11	0.07	0.10	0.28	− 0.08	− 0.11	0.11	0.08	0.06	0.17	0.00	− 0.02	− 0.04	0.00	0.01	1.00
2017
Average member age	1.00
Male percentage	− 0.08	1.00
Household size	− 0.22	0.11	1.00
Household income	− 0.13	0.12	0.34	1.00
Adult percentage	0.20	0.00	− 0.28	− 0.06	1.00
No high school percentage	0.00	0.00	0.08	− 0.14	− 0.30	1.00
Bachelor’s degree percentage	− 0.15	0.03	− 0.01	0.15	0.03	− 0.12	1.00
Number of vehicles	− 0.10	0.17	0.55	0.36	− 0.10	− 0.04	0.01	1.00
Home ownership	0.29	0.01	0.21	0.27	− 0.01	− 0.07	− 0.01	0.33	1.00
Number of trips per day	− 0.12	0.05	0.60	0.25	− 0.17	0.02	0.03	0.35	0.15	1.00
Travel time per day	− 0.09	0.06	0.33	0.15	− 0.08	0.03	0.00	0.21	0.07	0.04	1.00
Gas price	0.04	0.00	0.00	0.05	0.01	− 0.03	− 0.01	− 0.01	− 0.04	0.00	0.01	1.00
Shopping trip percentage	0.16	0.03	− 0.06	− 0.10	0.04	0.04	− 0.05	− 0.07	0.00	− 0.20	− − 0.06	0.00	1.00
Urban area	− 0.12	0.00	− 0.06	0.04	0.02	0.00	0.05	− 0.15	− 0.18	− 0.04	− 0.01	0.18	− 0.01	1.00
Population density	− 0.17	0.00	− 0.08	0.05	0.02	− 0.01	0.08	− 0.22	− 0.25	− 0.05	− 0.02	0.17	− 0.01	0.64	1.00
Daily Internet use	− 0.28	0.02	0.15	0.27	− 0.04	− 0.17	0.13	0.14	0.03	0.12	0.06	0.02	− 0.10	0.03	0.06	1.00