In 2021, R&D expenses decreased by 13% from 148 million yuan in 2020 to 128 million yuan. The reduction in the company's R&D investment is consistent with the loss of R&D personnel (from 491 to 430). What is the main reason for the loss of R&D personnel?

Changying Credit: Hello investors, the company's 2020 data includes the Beihang project. After excluding the Beihang consolidated data, the company's R&D expenses and R&D personnel both showed different year-on-year growth, with increases of about 16% and 15% respectively. Thank you.