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v3.19.2

Investments | 6 Months Ended
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Jun. 30, 2019
Investments |
Investments | 7 — Investments Our investments consist of corporate bonds that we have classified as available-for-sale and are summarized in the following tables:
|  |  | June 30, 2019
|  |  |  |  | Gross |  | Gross |  |  |
|  |  |  |  | Unrealized |  | Unrealized |  | Fair
|  | Cost |  | Gains |  | Losses |  | Value
Corporate bonds: |  |  |  |  |  |  |  |  |  |  |  |
U.S. corporations |  | $ | 4,433,867 |  | $ | 20,611 |  | $ | 1,348 |  | $ | 4,453,130
International corporations |  |  | 918,417 |  |  | 11,314 |  |  | — |  |  | 929,731
Total |  | $ | 5,352,284 |  | $ | 31,925 |  | $ | 1,348 |  | $ | 5,382,861
|  |  | December 31, 2018
|  |  |  |  | Gross |  | Gross |  |  |
|  |  |  |  | Unrealized |  | Unrealized |  | Fair
|  | Cost |  | Gains |  | Losses |  | Value
Corporate bonds: |  |  |  |  |  |  |  |  |  |  |  |
U.S. corporations |  | $ | 5,487,645 |  | $ | — |  | $ | 58,309 |  | $ | 5,429,336
International corporations |  |  | 918,417 |  |  | 2,162 |  |  | — |  |  | 920,579
Total |  | $ | 6,406,062 |  | $ | 2,162 |  | $ | 58,309 |  | $ | 6,349,915
Unrealized losses from the above investments for all periods presented are attributable to changes in interest rates. We do not believe any of these unrealized losses represent other-than-temporary impairments based on our evaluation of available evidence as of June 30, 2019.

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