Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Gross amount at beginning | $15,960.1 | $15,349.0 | $14,277.0 |
| Additions during period: |  |  |  |
| Acquisitions | 887.0 | 721.4 | 499.7 |
| Discretionary capital projects (1) | 258.1 | 173.5 | 120.7 |
| Discretionary ground lease purchases (2) | 189.8 | 180.4 | 150.4 |
| Redevelopment capital expenditures (3) | 213.6 | 177.3 | 138.8 |
| Capital improvements (4) | 161.2 | 94.0 | 65.6 |
| Start-up capital expenditures (5) | 71.3 | 113.1 | 158.1 |
| Other (6) | 45.2 | (3.0) | 106.4 |
| Total additions | 1,826.2 | 1,456.7 | 1,239.7 |
| Deductions during period: |  |  |  |
| Cost of real estate sold or disposed | (304.6) | (395.7) | (246.5) |
| Other (7) | (52.4) | (449.9) | 78.8 |
| Total deductions: | (357.0) | (845.6) | (167.7) |
| Balance at end | $17,429.3 | $15,960.1 | $15,349.0 |
Paragraphs:
AMERICAN TOWER CORPORATION AND SUBSIDIARIES SCHEDULE III—SCHEDULE OF REAL ESTATE AND ACCUMULATED DEPRECIATION (dollars in millions)
(1) Includes amounts incurred primarily for the construction of new sites.
(2) Includes amounts incurred to purchase or otherwise secure the land under communications sites.
(3) Includes amounts incurred to increase the capacity of existing sites, which results in new incremental tenant revenue.
(4) Includes amounts incurred to enhance existing sites by adding additional functionality, capacity or general asset improvements.
(5) Includes amounts incurred in connection with acquisitions or new market launches. Start-up capital expenditures includes non-recurring expenditures contemplated in acquisitions, new market launch business cases or initial deployment of new technologies or innovation solutions that lead to an increase in sitelevel cash flow generation.
(6) Primarily includes regional improvements and other additions.
(7) Primarily includes foreign currency exchange rate fluctuations and other deductions.
Question:
What was the percentage change of the balance at the end between 2018 and 2019?
Answer: ($17429.3-$15960.1)/$15960.1 = 9.21