• Aon average gross margin for 2023 was 48.54%, a 4.27% decline from 2022.
• Aon average gross margin for 2022 was 46.55%, a 3.17% increase from 2021.
• Aon average gross margin for 2021 was 45.12%, a 2.91% increase 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.