I'm pretty sure less than a decade.
Based on the price in https://coinmarketcap.com/currencies/bitcoin/ in 2013, the value was 100 usd and I think that's the first year it was recorded in value but I was read bitcoin was already traded before with less than a dollar in value.
So from less than a dollar and it reaches 100 usd, that's a big achievement already and that's a good value, but bitcoin does not stop, it continue to grow.
The pizza guy bought BTC in 2010 -
https://qz.com/1285209/bitcoin-pizza-day-2018-eight-years-ago-someone-bought-two-pizzas-with-bitcoins-now-worth-82-million/