Just added Week 43 numbers and I have some calculations.
At this point last year, the Switch had sod through exactly 56.7522631% of its 2018 Yearly total in Japan.
If that percentage holds for 2019, the Switch would finish this year with 4,912,516 units sold in Japan.
Hardware Comparison Threads:
Current Thread
Is Hardware Getting TOO Powerful?
Older Threads:
PlayStation/Xbox/Switch: 2022 Edition
PlayStation/Xbox/Switch Hardware Battle: 2021 Edition!
PlayStation 4/Xbox One/Nintendo Switch: 2019 vs. 2020
PlayStation 4/Xbox One/Nintendo Switch: 2018 vs. 2019
PlayStation 4/Xbox One/Nintendo Switch: 2017 vs. 2018
PlayStation 4: 2015 vs. 2016 vs. 2017