Between 2000 and 2010, killed or seriously injured (KSI) numbers have fluctuated between 61 and 84 casualties per year, and increased to 118 casualties in 2011.
Rhwng 2000 a 2010, mae nifer y rhai a gafodd eu lladd neu’u hanafu’n ddifrifol wedi amrywio rhwng 61 ac 84 bob blwyddyn, ac yn 2011 cynyddodd hyn i 118 o anafusion.