Took it from Chaos Angel (from ATRL)
Dec, 1 2019: Shallow - 940,744,016 (+36,096,655)
Always Remember Us This Way - 348,220,009 (+15,878,120)
Dec 1, 2020: Shallow - 1,330,954,058 (+30,007,075)
Always Remember Us This Way - 519,884,693 (+13,804,921)
Shallow kept ~83.1% and ARUTW kept ~86.9% of its monthly streams.
Shallow gained 390,210,042 streams and ARUTW gained 171,664,684 stream.
With these numbers, Shallow should gain ~324,264,545 streams and ARUTW ~149,176,610 streams over the next 12 months.
Dec 1, 2021 Estimated Totals:
Shallow ~ 1,655,218,603
ARUTW ~ 669,061,303
This also means that Shallow could hit 2B streams in early 2023 and ARUTW could hit 1B streams in late 2024.