The phrase "a massive decrease of" is correct and usable in written English.
It can be used when discussing a significant reduction in quantity, size, or intensity of something.
Example: "The report indicated a massive decrease of sales in the last quarter compared to the previous year."
Alternatives: "a substantial reduction in" or "a significant drop in".
"There's been a massive decrease of companies being able to fund us," she said, declining details for fear of damaging her relations with the companies.
From an investment high of £2.5 billion in 2015, investments are expected to plunge to £0.435 billion in 2019, marking a massive decrease of 82.6%.
Through modern medicine, the 20th Century saw a massive decrease of deaths from polio, measles, and typhoid, amongst others.
We found a massive decrease of the number of peripherin-positive fibers in epididymal and subcutaneous adipose tissue of Nscl-2 mutants at 8, 16 and 24 weeks after birth (Fig. 1Ae, f, Fig. 2).
In particular, RT-PCR analyses showed a massive decrease of E-cadherin levels mainly in SP+ A549 cells and a strong increase of Slug gene expression in SP−, SP+ and CD133+ fractions.
Altogether, our results indicate a massive decrease in total amount of sialic acid and a parallel increase of the acetylation of the remaining sialic acid residues in the GFB.
The program offers a birth dose of HBV vaccine plus a three-dose regimen of HBV-DPT vandine, and has resulted in a massive decrease in the prevalence of chronic HBV infection between those born in the early 1980s and those born in the present century.
Indeed, in U-2OS cells treated with 5 μM NBDHEX, a massive decrease in the association of TRAF2 with GSTP1-1 was evident even after 1 h of treatment.
Peace processes and disarmaments, as well as an uptick in security measures, have led to a massive decrease in the number of attacks across the continent.
U.S. military and Iraqi government officials hailed what they said was a massive decrease in violence, calling it a sign of the success of Operation Forward Together.
The letter then goes into detail about the owners' proposal, which the players say would have resulted in the players' share of revenue suffering a "massive" decrease.
