This is an interesting topic, and it needs to be expanded.

A competent example of describing a process without beginning and ending was created a long time ago.

On the stock exchange, we have a well-known and used indicator called the moving average.

When we apply it to price data using different time periods of the indicator, we see the full picture and trends.

Without a doubt, it can be used to describe any data that does not have a reference point.

So, we take our weekly inflation data and plot on them the curves of average percentage growth for a certain period, presented in annual terms.

Figure 1.

So, we see a bunch of curves representing inflation in different time dimensions, and we see the direction of the curves relative to each other.

When curves with a short period of time overtake curves with a long period and cross them, this is called a growing trend.