Rolling window implementation

I'm interested in writing a fixed-length table data structure for time-series analysis, which works like a rolling window, meaning each new row inserted causes the oldest row to be dropped. I have a working example using a HashMap of Vecs, but I'm wondering if I should instead use VecDeque. Is indexing of VecDeque as good as, or better than, Vec?

Never mind, I found my answer after some more searching.