This is 5 year chart of Tenaga.
Use 2016 as starting point. The chart is 'unadjusted for it's dividends' etc...
I use this so that I have the actual reference price of what Tenaga was trading at during that time...

Tenaga last 5 years profits...
2016 -- 7.368 Billion
2017 -- 6.904 Billion
2018 -- changed calendar year ...

so I use profit of 3.724 Bil (ignoring 4 months profit of 2.756 Billion)
2019 -- 4.529 Billion
2020 -- 3.593 Billion
Clearly, despite the so-called monopoly business status, Tenaga does not have a strong moat on its profits. ( Yup, there are many who has been misguided. They believe that monopoly business is a sure win but clearly it's not.
Logically and understandably, its business is affected if there is a change of government or change of govt policy.
The confirmation that Tenaga's earnings was declining...

Nov 2018 and it's marked with the dotted lines on the chart below... was it or was it not a good time to sell?

The dividends...

So if one had purchased on May 2016 (5 years ago ma...)
The price would be around 14.00.
the dividends collected since then...
32 sen + 61 sen + 21.41sen + 53.27 sen + 100 sen + 80 sen = 347.68
Price of Tenaga as of yesterday closing is 9.95.
Current share price + total dividends collected => 9.95 + 3.4768 = 13.4268.
cost of investment was 14.00.
err... macam rugi duit sikit.....