
Given the following passage

"The term prime minister in the sense that we know it originated in the 18th century in the United Kingdom when members of parliament disparagingly used the title in reference to Sir Robert Walpole. Over time, the title became honorific and remains so in the 21st century.",

answer the following question. Note that the answer is present within the text.

Question: What allows the estimation of the duration of the term prime minister as we use today? 

originated in the 18th century
