Should I put "that"?

Hello. I'd like to know whether I should put "that" in the next sentence.

In recent years, energy consumption per person
in Japan has been at almost the same level as [that] in European　countries.

Thank you.

I'd leave it out.

lol I'd put it in... Either way works.

I would put it in there.

I would leave it out.

I say in.

Here, there is also the question concerning whether "that in" should be included or not.

Regarding the actual question:

If I am tired and under stress to finish a piece of written work, I would include "that".

If I am full of energy and feel that my written work that includes the subject sentence is very good, I would not include "that"/"that in".

Further to the above message:

If you write briefing papers for the President of the United States, the Vice President of the USA, the Prime Minister of the UK, UK Government ministers etc etc, then leave "that" out, as these peoples' time is crucially important. This same advice is perhaps pertinent to sending messages during emergency situations. However, I take no responsibility for anything to do with messages or sending messages during emergency situations - you will need to investigate this further yourself.

For other circumstances, the advice in the previous message is pertinent.