Chart 2 shows the monthly trends in the percentage of total tax returns received via paper for the year, which is one of our main performance measures (PM1a).
Mae Siart 2 yn dangos y tueddiadau misol yng nghanran cyfanswm y ffurflenni treth a dderbyniwyd ar bapur am y flwyddyn, sef un o'n prif fesurau perfformiad (PM1a).