Question: How many books were illustrated each Christmas for eight years by the man who, along with Walter Crane and Kate Greenaway, was among the strongest contributors to the child's nursery motif for during the 19th century? 
Sentence (from "Walter Crane"): He is considered to be the most influential, and among the most prolific, children’s book creator of his generation and, along with Randolph Caldecott and Kate Greenaway, one of the strongest contributors to the child's nursery motif that the genre of English children's illustrated literature would exhibit in its developmental stages in the latter 19th century.
Relevant evidence: Yes