The following table gives the number of patients visiting a dental clinic for the issues related to their oral health during the months September, October, November and December 2018. Study the table carefully and answer the question that follows.

Month (2018)	Filling	Root canal	Tooth extraction	Implants
September	180	480	570	260
October	560	770	620	470
November	940	1080	890	220
December	820	590	530	1040

What is the ratio of the total number of patients in September to the total number of patients in December in 2018?