Five thousand deckchairs were removed and used as evidence

I'm approached by T.Aldous:

"I told the staff at Senebene to take a daily note of the number on the visitor counters as it's evident from the downloaded spreadsheets that the counter isn't recording any figures. Beryl's sent me the figures but something's not right: every day the figure's 1559. Can you find out what's going on?"

"Perhaps the counter isn't recording any figures so the number isn't changing."