Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
|  |  | (inthousands) |  |
| Long-lived assets: |  |  |  |
| United States | $933,054 | $784,469 | $575,264 |
| Europe | 72,928 | 73,336 | 77,211 |
| Korea | 28,200 | 24,312 | 19,982 |
| China | 6,844 | 5,466 | 1,906 |
| Taiwan | 6,759 | 7,922 | 7,970 |
| Japan | 5,750 | 3,327 | 1,083 |
| Southeast Asia | 5,542 | 3,715 | 2,179 |
|  | $1,059,077 | $902,547 | $685,595 |
Paragraphs:
Note 19: Segment, Geographic Information, and Major Customers
The Company operates in one reportable business segment: manufacturing and servicing of wafer processing semiconductor manufacturing equipment. The Company’s material operating segments qualify for aggregation due to their customer base and similarities in economic characteristics, nature of products and services, and processes for procurement, manufacturing, and distribution.
The Company operates in seven geographic regions: United States, China, Europe, Japan, Korea, Southeast Asia, and Taiwan. For geographical reporting, revenue is attributed to the geographic location in which the customers’ facilities are located, while long-lived assets are attributed to the geographic locations in which the assets are located.
Revenues and long-lived assets by geographic region were as follows:
In fiscal year 2019, four customers accounted for approximately 15%, 14%, 14%, and 14% of total revenues, respectively. In fiscal year 2018, five customers accounted for approximately 25%, 14%, 14%, 13%, and 12% of total revenues, respectively. In fiscal year 2017, five customers accounted for approximately 23%, 16%, 12%, 11%, and 10% of total revenues, respectively. No other customers accounted for more than 10% of total revenues.
Question:
Why did the Company's material operating segments qualify for aggregation?
Answer: due to their customer base and similarities in economic characteristics, nature of products and services, and processes for procurement, manufacturing, and distribution