定年退職	542,256	99.5%	
停年退職	2,914	0.5%

I agree with Brian regarding "reaching retirement age".

@@ -8,0 +9 @@
+<ke_inf>&rK;</ke_inf>
@@ -17 +18 @@
-<gloss>(compulsory) retirement (e.g. on reaching the age of 65)</gloss>
+<gloss>(compulsory) retirement (on reaching retirement age)</gloss>
@@ -19 +19,0 @@
-<gloss>reaching retirement age</gloss>

https://www.boj.or.jp/en/about/press/koen_2019/ko190306a.htm

Improvements in Employment of Women and the Elderly
[paragraph on women]

Moreover, Chart 2 also shows that employment of the elderly has been growing. However, in the case of the elderly, the share of non-regular employees has been rising. The reason is likely that many are hired as temporary or part-time workers after reaching retirement age. Because Japan's population is aging, this means that it is unlikely that the share of non-regular employees in employment as a whole will decrease. However, looking at employees between 15 and 64 years of age, the share of non-regular employees has been declining since around 2014.

また、同じ図2に見るように、高齢者の雇用も伸びています。ただし、高齢者の場合は、非正規の割合が上昇しています。これは定年退職後、嘱託や非常勤として雇われる高齢者が多いからだと思われます。日本は高齢化が進んでいる訳ですから、このことは、雇用全体として非正規の割合が低下することが難しいということを意味します。しかし、15－64歳までの雇用者を見れば、2014年頃から、非正規の割合が低下しています。

Small note of little importance, the previous translation coincidentally ran into my  嘱託(社員) edit. The workers were probably "RE-hired after reaching (mandatory) retirement age".  

And I found the original source.
https://www.boj.or.jp/en/about/press/koen_2019/ko190306a.htm

I was going to suggest that context probably made things clear. Instead, it looks like this is an official Japanese translation of a Japanese source document that dropped some (perhaps non-critical) nuances.

定年退職	542157	  
定年退職し	73046	  
定年退職した	34855	 

daijs: suru
［名］(スル)一定の年齢に達したことを事由に退職すること。「65歳で会社を―する」

Add [vs,vi] 

If it were me, I wouldn't have added the GG5 gloss of "reaching retirement age".  It definitely works in some contexts, but this term doesn't mean "turned 65".  It means "turned 65 and had to retire".  In English, I feel like even after saying "After reaching retirement age...", you would *still* have to add "...she left the company (...and started a small business)".  

Take this reverso translation:
これは定年退職後、嘱託や非常勤として雇われる高齢者が多いからだと思われます。
"The reason is likely that many are hired as temporary or part-time workers after reaching retirement age."

I feel like the translator lost a step. I think "after mandatory retirement" would have been clearer.

Also, you can "reach retirement age" without being employed. You definitely need a job to 定年退職. (One more reason why the previous translation ends up ambiguous).

@@ -14,0 +15,2 @@
+<pos>&vs;</pos>
+<pos>&vi;</pos>