Taxable basis in aggregate initial cost

[Table of Contents](#i89c3c9328e454b30b2c14123b867f3f0_7)(4)     Date of lease or acquisition represents the date we leased the facility or acquired the facility through purchase or acquisition. (5)    Includes various IBXs that are under initial development and costs incurred at certain central locations supporting various IBX functions.  
The aggregate gross cost of our properties for federal income tax purpose approximated $29.1 billion (unaudited) as of December 31, 2021. The following table reconciles the historical cost of our properties for financial reporting purposes for each of the years in the three-year period ended December 31, 2021 (in thousands). Gross Fixed Assets:

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  | 2021 |  | 2020 |  | 2019 |
| Balance, beginning of period | $ | 20,161,785  |  |  | $ | 16,927,332  |  |  | $ | 15,020,198  |  |
| ASC 842 adoption impact (1) | —  |  |  | —  |  |  | (276,671) |  |
| Additions (including acquisitions and improvements) | 2,977,992  |  |  | 3,110,907  |  |  | 2,632,472  |  |
| Disposals | (648,516) |  |  | (446,864) |  |  | (463,485) |  |
| Foreign currency transaction adjustments and others | (585,206) |  |  | 570,410  |  |  | 14,818  |  |
| Balance, end of year | $ | 21,906,055  |  |  | $ | 20,161,785  |  |  | $ | 16,927,332  |  |

Accumulated Depreciation:

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  | 2021 |  | 2020 |  | 2019 |
| Balance, beginning of period | $ | (6,399,477) |  |  | $ | (5,329,182) |  |  | $ | (4,517,016) |  |
| ASC 842 adoption impact (1) | —  |  |  | —  |  |  | (7,846) |  |
| Additions (depreciation expense) | (1,224,874) |  |  | (1,036,452) |  |  | (926,046) |  |
| Disposals | 149,231  |  |  | 109,230  |  |  | 128,352  |  |
| Foreign currency transaction adjustments and others | 200,260  |  |  | (143,073) |  |  | (6,626) |  |
| Balance, end of year | $ | (7,274,860) |  |  | $ | (6,399,477) |  |  | $ | (5,329,182) |  |



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| --- | --- | --- |
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(1)     Upon the adoption of Topic 842 on January 1, 2019, we de-recognized certain fixed assets under built-to-suite leases due to the conversion of certain build-to-suit leases to operating leases. See Note 1 within the Consolidated Financial Statements.F-71  