Figure 1.

(a) A representation of the normal distribution, where the probability of an event happening is symmetrically dispersed about the mean (μ), with 68.27%, 95.45% and 99.73% of all events occurring within one, two and three standard deviations (σ), respectively, from the mean. (b) The frequency of PDB depositions, grouped by year, from MX, EM, NMR and all three techniques combined. (c, d) Gaussian fits (shown in green) of the depositions from NMR and MX, respectively. The 95% confidence limits are highlighted in pink.