The phrase "significant number" refers to a large or important quantity of something. It indicates that the amount being referred to is noteworthy or has a considerable impact. Full definition
So much has been wasted in terms of corruption; there's no value for money in significant number of projects undertaken. (3news.com)
However despite critical success and numerous awards, our games just haven't sold in significant numbers. (housemarque.com)
The study included over 500 respondents from a wide array of industries, including manufacturing, technology, and finance, with significant numbers of C - suite and director - level respondents. (businessinsider.com)