1 years old now in 2023 - what year born?

Today, 22 March 2023 if a person is 1 years old now, what year was he born? See below:

If 1 years old, year of birth is:
2021 or 2022*

*It depends on whether he was born before or after 1 January 2022.

If now 1 years and his year of birth 2021 if he was born after 22 March 2021 until 31 december 2021 inclusively, and his year of birth is 2022 if he was born from 1 January 2022 to 22 March 2022.

Other examples:

If now 4 years, year of birth 2018 or 2019
If now 13 years, year of birth 2009 or 2010
If now 23 years, year of birth 1999 or 2000
If now 73 years, year of birth 1949 or 1950

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