For those not keeping score, Roc Marciano dropped four albums this year: Rosebudd's Revenge 2: The Bitter Dose, Behold a Dark Horse, KAOS (with DJ Muggs), and now Pimpstrumentals, his first instrumental album.
One could argue that to find a comparable run you'd have to go back to MF Doom circa 2003-2004 (another Long Islander for those who are keeping score).
Coincidentally, Pimpstrumentals is brought to you by Adult Swim, the same label that put out Doom and Danger Mouse's Danger Doom album, The Mouse and The Mask, which arguably bookended the aforementioned run.