Example with missing values
['A', 1853, 'RR', ?, 2, 'N', 'DECK', 'WOOD', '?', 'S', 'WOOD']
Imputed values:
['A', 1853, 'RR', 804, 2, 'N', 'DECK', 'WOOD', 'SHORT', 'S', 'WOOD']
['A', 1853, 'RR', 804, 2, 'N', 'DECK', 'WOOD', 'SHORT', 'S', 'WOOD']
