I've fabricated a quick visual overview in MS Paint of the total market capitalization of crypto on the 21st of August since 2013.
It is interesting to see that the total market cap seemed a bit stagnant in previous years from our current viewpoint. Ofcourse, it only seemed stagnant and there was definitely a lot of dynamic in cryptoland in these years; the ATH of november 2013, the appearant nosedive of Bitcoin in january 2015, lots of altcoins rising and dying, and so on ...
2015 wasn't a very good year for crypto; on the 21st of August that year, the total market cap was only $4 billion compared to $7,35 billion exactly a year earlier. In 2016, crypto grew slowly again and eventually reached the level we saw three years earlier, in november/december 2013. And yes, this year digital money really took off and who knows where we are in a couple of years ... !