• Duolingo average return on investment for 2023 was -3.32, a 74.06% decline from 2022.
• Duolingo average return on investment for 2022 was -12.8, a 3757.14% decline from 2021.
• Duolingo average return on investment for 2021 was 0.35, a 99.57% decline from 2020.

Roi - return on investment can be defined as an indicator of how profitable a company is relative to its assets invested by shareholders and long-term bond holders. Calculated by dividing a company's operating earnings by its long-term debt and shareholders equity.