As of my last update in January 2022, Bitcoin's existence spans over 13 years, not 15. However, I can provide you with some interesting facts about Bitcoin returns during its existence:

1. Early Days: Bitcoin was created in 2009 by an unknown person or group using the pseudonym Satoshi Nakamoto. In its early days, Bitcoin had virtually no monetary value, and miners could generate thousands of coins with minimal computational power.

2. Volatility: Bitcoin has experienced extreme price volatility throughout its existence. From its inception in 2009 to 2022, Bitcoin's price has witnessed numerous boom-and-bust cycles, with price fluctuations of hundreds or even thousands of percent within short periods.

3. Parabolic Growth: Despite its volatility, Bitcoin has delivered impressive long-term returns. For example, Bitcoin's price increased from less than $1 in 2010 to over $60,000 in 2021, representing a staggering return on investment for early adopters and investors.

4. Market Cycles: Bitcoin's price tends to move in cycles, characterized by periods of rapid appreciation (bull markets) followed by sharp corrections (bear markets). These market cycles are driven by various factors, including investor sentiment, regulatory developments, macroeconomic trends, and technological advancements.

5. Halving Events: Approximately every four years, the supply of new bitcoins issued to miners is halved in a process known as the "halving." These halving events are programmed into Bitcoin's protocol and serve to reduce the rate of inflation over time. Historically, Bitcoin's price has experienced significant rallies following halving events due to reduced supply issuance and increased demand.

6. Institutional Adoption: In recent years, institutional investors, corporations, and financial institutions have increasingly embraced Bitcoin as a store of value and a hedge against inflation. This institutional adoption has contributed to Bitcoin's legitimacy as an investable asset and has likely played a role in driving up its price.

7. Global Acceptance: Bitcoin has gained acceptance as a legitimate form of payment by an increasing number of merchants, businesses, and online platforms worldwide. Companies like PayPal, Tesla, and Microsoft now accept Bitcoin as a means of payment, further solidifying its mainstream adoption.

8. Limited Supply: Bitcoin's maximum supply is capped at 21 million coins, making it a deflationary asset. Unlike fiat currencies, which can be inflated by central banks, Bitcoin's fixed supply provides protection against monetary debasement and may contribute to its long-term value proposition.

9. Market Cap Milestones: Bitcoin's market capitalization, which represents the total value of all bitcoins in circulation, has grown exponentially over the years. Bitcoin has surpassed several significant milestones, including reaching a market cap of over $1 trillion for the first time in early 2021.

10. Global Impact: Bitcoin's emergence has had far-reaching implications beyond finance, influencing various industries, technological developments, and socio-economic paradigms. Its decentralized nature, censorship resistance, and borderless nature have the potential to disrupt traditional financial systems and empower individuals worldwide.

These facts highlight the remarkable journey of Bitcoin over the past decade, from its humble beginnings as an experimental digital currency to its current status as a globally recognized and increasingly mainstream asset class.