Table 1 Summary Statistics for Iowa Lakes Data

Variable	2002	2003	2004	2005	2009	2014	All Years
Households	3,270	4,271	3,528	3,133	4,890	3,223	22,315
Trips (all households)	6.41	6.94	6.57	6.92	6.25	6.54	6.59
Trips (households with positive trips)	10.75	11.09	10.60	11.08	10.42	11.22	10.83
Travel cost (all sites) ($)	137	139	138	143	139	97	133
Travel cost (trips taken) ($)	59	63	66	67	62	36	60
Age (26-34)	0.12	0.10	0.09	0.07	0.05	0.03	0.08
Age (35-49)	0.3	0.31	0.29	0.29	0.24	0.21	0.28
Age (50-59)	0.22	0.23	0.24	0.26	0.26	0.25	0.24
Age (60-75)	0.21	0.23	0.26	0.26	0.32	0.44	0.28
Age (76+)	0.09	0.10	0.11	0.11	0.13	0.06	0.10
Male respondent	0.69	0.67	0.66	0.67	0.68	0.69	0.68
Household size	2.63	2.57	2.47	2.52	2.45	2.47	2.52
College (share with post-high school education)	0.68	0.6	0.68	0.70	0.70	0.75	0.70
Income category 1 (<$25,000)	0.18	0.19	0.14	0.16	0.10	0.10	0.15
Income category 2 ($25,001-$50,000)	0.34	0.33	0.33	0.31	0.21	0.22	0.29
Income category 3 ($50,001-$75,000)	0.26	0.25	0.27	0.25	0.46	0.31	0.31
Income category 4 ($75,001-$100,000)	0.13	0.12	0.13	0.14	0.10	0.16	0.13
Income category 5 (>$100,000)	0.90	0.11	0.12	0.13	0.11	0.22	0.13
Home-county weekend precipitation (mm)	1.91	1.71	2.47	1.52	2.50	2.09	2.06
Home-county weekend temperature (°C)	9.89	8.62	9.26	9.66	8.30	8.20	8.92

Note: This table provides mean values of trips, travel costs, and demographics. The age group of < 25 is treated as the base group and not reported here. The household size is truncated at 10. All households that do not report income are assigned to category 3. Annual average home-c ounty weekend weather variables are compiled from the PRISM Climate Group (monthly data available at http://prism.oregonstate.edu). Travel costs are expressed in 2002 US$.