On the Dash website (https://docs.dash.org/en/latest/index.html), it states that "In addition to Bitcoin’s feature set, Dash currently also offers instant transactions (InstantSend), private transactions (PrivateSend)...".
Based on this I came to the conclusion that there are two options for the Dash users, InstantSend and PrivateSend. Hence the assumption that since PrivateSend is currently a limited % of transactions, the majority is InstantSend. Great project, but I still see other similar projects beating them