How many transactions use SegWit, measured on one sample block at each difficulty adjustment, straight from our node (getblockstats).
SegWit activated in August 2017. SegWit transactions pay less for the same payload, so their share is a simple way to see how much Bitcoin usage has shifted since.
At the height of each difficulty adjustment we ask our node for that block's stats and store the share of SegWit transactions. Before activation the value is zero.
One block out of every 2016: good for the trend, not for a given day's exact figure, and an unusual block can stick out. The series doesn't separate Taproot from other SegWit outputs.
How address types affect your wallet's privacy: privacy and self-custody tools.
More network data from our own node on the NodeWitness Network page.