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Sgr A* is the variable electromagnetic source associated with accretion ontothe Galactic center supermassive black hole. While the near-infrared (NIR)variability of Sgr A* was shown to be consistent over two decades,unprecedented activity in 2019 challenges existing statistical models. Weinvestigate the origin of this activity by re-calibrating and re-analyzing allof our Keck Observatory Sgr A* imaging observations from 2005-2022. We presentlight curves from 69 observation epochs using the NIRC2 imager at 2.12 $\mu$mwith laser guide star adaptive optics. These observations reveal that the meanluminosity of Sgr A* increased by a factor of $\sim$3 in 2019, and the 2019light curves had higher variance than in all time periods we examined. We findthat the 2020-2022 flux distribution is statistically consistent with thehistorical sample and model predictions, but with fewer bright measurementsabove 0.6 mJy at the $\sim$2$\sigma$ level. Since 2019, we have observed amaximum $K_s$ (2.2 $\mu$m) flux of 0.9 mJy, compared to the highest pre-2019flux of 2.0 mJy and highest 2019 flux of 5.6 mJy. Our results suggest that the2019 activity was caused by a temporary accretion increase onto Sgr A*,possibly due to delayed accretion of tidally-stripped gas from the gaseousobject G2 in 2014. We also examine faint Sgr A* fluxes over a long timebaseline to search for a quasi-steady quiescent state. We find that Sgr A*displays flux variations over a factor of $\sim$500, with no evidence for aquiescent state in the NIR.

Near-Infrared Flux Distribution of Sgr A* from 2005-2022: Evidence for an Enhanced Accretion Episode in 2019