a decreasing trendP < 0.0001
The incidence rate showed a rapidly increasing trend from 1975 to 1987, with an APC of 3.3% (95% confidence interval [CI] = 2.8–3.9%, P < 0.0001), while this increase slowed from 1988 to 2001 (APC = 0.8%, 95% CI = 0.4–1.1%, P < 0.0001), and was followed by a decreasing trend from 2002 to 2016 (APC= −0.7%, 95% CI= −0.9% to −0.5%, P < 0.0001).