This paper examines the data accuracy and number of altmetric counts reported by Mendeley, altmetric.com and PlumX at two points in time: June 2017 and April 2018 for the dataset of 2,728 articles and reviews published in JASIST between 2001 and 2014. The findings show growth in the number of citations and Mendeley readers over time. In addition, the results also show that there are differences in the altmetric counts reported by the two-altmetric aggregators Altmetric.com and PlumX.