There ya go: Sample size and 3-yr recalc
And re sample size, consider that those stats (6.75 ERA in 30.2 IP) could be nothing more than two really bad outings. IOW, he's not really that far removed from a respectable ERA.
I'm reminded of Mike Marshall in 1974 & 1975. He was stellar (won a Cy Young award out of the 'pen) in '74; his ERA that year was 2.42. The following year his ERA was 3.29; not bad, but not nearly as nice as the year before. However, if you take away a single dreadful 1975 outing - 9 earned runs allowed in a 2-inning, early-May stint against the Pirates - his ERA would've been 2.60, which is not significantly higher than his 1974 ERA.