[8] Cost of sales and other functional costs

The total cost of materials recognized under functional costs in the consolidated income statement went down by €535.9 million to €5,181.5 million in 2023 (2022: €5,717.5 million), mainly due to the easing of material prices.

The total personnel expenses recognized under functional costs rose by €320.9 million to €3,169.6 million (2022: €2,848.7 million). This rise can be explained by the growth in the average number of employees for the year and general salary increases.

Personnel expenses included wages and salaries of €2,534.1 million (2022: €2,274.9 million), social security contributions of €565.0 million (2022: €500.1 million), and post-employment benefit costs and other benefits of €70.5 million (2022: €73.6 million). Post-employment benefit costs and other benefits comprised a current service cost from defined benefit pension plans of €26.5 million (2022: €47.7 million). The interest cost from the unwinding of the discount on estimated pension obligations is not recognized under personnel expenses and is instead reported under financial expenses as a component of interest expense.

Depreciation expenses on property, plant and equipment together with amortization expenses on intangible assets totaled €1,046.6 million in the reporting year (2022: €1,013.4 million); these expenses are recognized under functional costs.

In 2022, the cost of sales and selling expenses had included impairment losses of €10.9 million on inventories and impairment losses of €3.4 million on trade receivables and lease receivables of the Russian subsidiaries in the Industrial Trucks & Services segment that are to be sold. Further information can be found in note [27].