The Sonoma County Fair’s 11-day meet showed a decline in ontrack wagering and all-sources wagering this summer. Ontrack wagering at Santa Rosa declined 11 percent to $2,787,809 from $3,120,021 in 2016. All-sources handle, including out-of-state and advance-deposit wagering, was down 14 percent to $10,553,939 from $12,253,383.        The fair’s handle was hampered in both years by the decision to hold three days of racing when the fair wasn’t operating. There was a 9.4 percent decrease in daily ontrack handle and an 8 percent decrease in daily all-sources wagering on those non-racing dates.