Good question! It's spiking up on weekends, the reason for that is that corporate networks are not as incentivized as large public ISPs to adopt IPv6.
They have a lot more customers and are more directly affected by IPv4 exhaustion, especially the mobile providers.
I'd guess work VPNs don't implement IPv6 (why would they, if they only need to share 1 IPv4), which results to home internet usage being higher on the weekends.
