法定 ほうてい耐用 たいよう年数 ねんすうでしょう
hōteitai yōnensūdeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 法定耐用年数

1. Probably the legally defined lifespan.; Likely the statutory useful life.

Polite
Presumptive
Conjecture