How to check 1999, 2021, 2022 without 年 in target?

In source, there are three segments, one segment is 1999, one is 2021 and one is 2022, but in Target language (In Chinese), the word “年” should be added after 1999, 2021 and 2022,
ie,
Source Target
1999 1999 年
2021 2021 年
2022 2022 年

But sometimes, duo to pre-translation or omission, these segments in Target were not added 年 after the year.
ie.
Source Target
1999 1999
2021 2021
2022 2022

Could you help solve the problem: How to check 1999, 2021, 2022 without 年 in target?

The following search should help you find all numbers between 1000 and 2999 that do not have the word 年 after that number in target:

Source: "(<[12][0-9]{3}>)=1"
Target: -"<@1> 年"
PowerSearch: On
Search mode: Regular Expressions

It worked perfectly. Your regular expression is so simple that it is worth learning.

Thank you very much.

I used this Regex to find missing 年, but it was not so good.

Source: “(^(17|18|19|20)*)=1”
Target: “@1” - \年
PowerSearch: On
Search mode: Regular Expressions.