How has the lottery evolved in the town over the years, and how does this contribute to the meaning of the text?

From the text:

There was the proper swearing-in of Mr. Summers by the postmaster, as the official of the lottery; at one time, some people remembered, there had been a recital of some sort, performed by the official of the lottery, a perfunctory. tuneless chant that had been rattled off duly each year; some people believed that the official of the lottery used to stand just so when he said or sang it, others believed that he was supposed to walk among the people, but years and years ago this part of the ritual had been allowed to lapse. There had been, also, a ritual salute, which the official of the lottery had had to use in addressing each person who came up to draw from the box, but this also had changed with time, until now it was felt necessary only for the official to speak to each person approaching.