7. CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Cash, cash equivalents and short-term investments consisted of the following (in thousands):

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Cash equivalents and short-term investments include the following securities with gross unrealized gains and losses (in thousands):

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As of December 31, 2021 and 2020, our cash equivalents and short-term investments had a weighted-average time to maturity of approximately 196 days and 78 days, respectively. Our short-term investments are classified as available-for-sale securities. Accordingly, we have classified certain securities as short-term investments on our balance sheets as they are available for use in the current operations. As of December 31, 2021, we had no investments that had been in a continuous unrealized loss position for more than 12 months. As of December 31, 2021, a total of 39 individual securities had been in an unrealized loss position for 12 months or less, and the losses were determined to be temporary. The gross unrealized losses above were caused by interest rate increases. No significant facts or circumstances have arisen to indicate that there has been any significant deterioration in the creditworthiness of the issuers of the securities held by us. Based on our review of these securities, including the assessment of the duration and severity of the unrealized losses, there were no other-than-temporary impairments for these securities as of December 31, 2021.

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The following table shows the fair value and gross unrealized losses of our investments in individual securities that are in an unrealized loss position, aggregated by investment category (in thousands):

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