Fig. 2

Annual operation volume for CHD and the cyanotic CHD proportion in children below 14 years old from 2005 to 2017. Chart a shows the annual cases of surgery for right-to-left shunt CHD, complex mixed defect CHD and total cyanotic CHD from 2005 to 2017. Chart b demonstrates the cyanotic CHD proportion (of total CHD in children below 14 years old) from 2005 to 2017