I performed a rolling window (i.e. do full sample, then next 4 observations until the last, and so on...) k-fold test for out of sample testing due to limited number of observations.
From the MAPE results, it seems like that with sample size it increases and sort of reaches a ceiling at a certain sample size.
For the MAE results, the MAE falls until the middle of the sample and starts rising again the larger the sample gets.
I'm new to this and am not sure how to interpret these results and would appreciate any help on this issue.