Of course, there are times in which BTC's price is fluctuating a lot, including several periods in which it dropped in price by more than 50%, and even in the ballpark of 70% to 80%, but we can still zoom out and see that the increase in value (price) has been continuously in the upwards direction, even if we have several extended periods in which it had been dropping in price or not really going up in price.
There is something wrong with the numbers in that chart. It is like people make charts and they just guess
If it is merely referring to the BIG dips, then maybe we could look at the BIG dips like this:
2011 - From $32 to $2 = 93.75%
2013a - From $263 to $63 = 76%
2013b - From $1,163 to $153 = 87%
2017 - From $19,666 to $3,124 = 84% (this one looks right)
2020 - From July 2019 $13,880 to $3,850 = 72% or alternatively From February 2020 - $10,200 to $3,850 = 62%
2021 - From late 2021 $69,000 to $15,479 = 87.5% and probably the one they are referring to is from early 2021 $64.5k-ish to $28.8k-ish. = 55%
But there have been various other BIG dips in the midst of those dips. There were many that were greater than 25%.. Difficult to have confidence in a chart that is not very close to getting the numbers right when they are specifically pointing out numbers in their chart... ..