Saku,
I don't at this point have long term data collection compiled for the issues that we've faced. That said, we have two 100G transport links that have a regular background level of input errors at ranges that hover between 0.00055 to 0.00383 PPS on one link, and none to 0.00135 PPS (that jumped to 0.03943 PPS over the weekend). The range is often directionally associated rather than variable behavior of a single direction. The data comes from the last 24 hours, the two referenced links are operated by different providers on very different paths (opposite directions). Over shorter distances, we've definitely seen input errors that have affected PNI connections within a datacenter as well. In the case of the last PNI issue, the other party swapped their transceiver, we didn't even physically touch our side; I note this only to express that I don't think this is just a case of the transceivers that we are sourcing.
Comparatively, other than clear transport system issues, I don't recall this sort of thing at all with 10G "wavelength" transport that we had purchased for years prior. I put wavelengths in quotes there knowing that it may have been a while since our transport was a literal wavelength as compared to being muxed into a 100G+ wavelength.