Three numbers tell this story: (1) Over the past decade, 27 percent of deer ticks tested across Connecticut were positive for Lyme disease; (2) so far this year, it’s 38 percent; (3) in Darien so far this year, it’s 47 percent. The high Darien percentage was the case with the 20 ticks sent to the laboratory at the state agricultural experiment station in 2017 up to Easter (April 16). The rate has stayed the same — out of a total of 30 ticks tested so far this year, 14 (47 percent) have tested positive for Lyme. Any Darien resident can bring a tick to the town Health Department for testing. Only ticks found on people (not pets) are sent to the state laboratory, town Health Director David Knauf says.