fee dependence

Hello Miss,for March 2020 Q3(b) fee dependence

“the Code states that an audit firm’s independence is threatened and should be reviewed if the total fees from a single client exceed 15% of its total fee income for two consecutive years. In this case, the 15% limit has been exceeded in both 20X4 and 20X5 and following the listing of the company’s shares in September 20X5, Moritz & Co is required to review its dependence on the client.”

Why the assess of fee dependence not start from the client become listed? but before it? (FOR both 20×4 and 20×5, the client Co still unlisted)

thank you.