Supermoon Lunar Eclipse Sept 27, 2015

I don't understand the dates at play here. It was seemingly every 18 years, but from 1982-2015 it jumped 33 years? Why is that? 1910 (+18=) 1928 (+18=) 1946 (+18=) 1964 (+18=) 1982 [+33=] 2015 (+18=) 2033


My guess is that Christ's life on this planet consisted of 33 years. What do you think??