https://www.jstage.jst.go.jp/article/dsj/11/0/11_11-DS4/_article

Second URL should be: http://dx.doi.org/10.1890/1051-0761(1997)007%5B0330:NMFTES%5D2.0.CO;2

I made a diagram (derived from a diagram in an earlier publication) that presents this data (and metadata) loss really well: Research Data and Metadata at Risk: Degradation over Time as part of a paper I co-authored on this subject, Facilitating Data Sharing in the Behavioral Sciences.