"Accumulation rates" refers to the speed or rate at which something collects or grows over time. It describes how quickly things accumulate or build up. Full definition
The cash value accumulation rate of investment is generally much lower than rates provided through other investment vehicles. (insuranceblogbychris.com)
Figure 3 shows that the contours have the closest spacing along the west margin and in the southeast, just as the high accumulation rates in those areas would suggest. (skepticalscience.com)
This northern area has low accumulation rates, and a shorter less intense melt season. (skepticalscience.com)