Highest salary at Mercer County in year 2022 was $215,033. Number of employees at Mercer County in year 2022 was 1,221. Average annual salary was $72,325 and median salary was $67,655. Mercer County average salary is 54 percent higher than USA average and median salary is 56 percent higher than USA median salary. From 2021 to 2022, the average salary of employees at this employer increased 0.5 percent.