• SLM average gross margin for 2023 was 67.27%, a 17.25% decline from 2022.
• SLM average gross margin for 2022 was 81.29%, a 0.71% decline from 2021.
• SLM average gross margin for 2021 was 81.87%, a 9.54% decline from 2020.

Gross margin can be defined as a company's total sales revenue minus its cost of goods sold, divided by the total sales revenue, expressed as a percentage.