I am doing time-series analysis in python for the dataset given below-
The plot for the above time series seems to be non-stationary for me because on observing it looks like consisting of some trend.
The plot for the above time series is as given-
The above plot is converted into stationary time series by taking log and then the difference between previous and succeeding values.
I have plotted corresponding ACF and PACF plot for that non-stationary time series which is given below-
From the above ACF it is clear to me that curve cutoff after 1th lag, and also in PACF plot no of ticks outside cutoff is 1. But from these two plots how I should choose the type of model (ARMA or ARIMA). If it is ARMA model then what is (p,q) and Why. Or if it is ARIMA model then what is (p,d,q) and Why?.