TWO DYNAMICS. “The situation in farmland appears to be quite distinct from that in urban centres. A major decline in farmland began in the late 1970s, but after a decrease of about 60% the population had stabilised by about 1995.”
https://www.britishbirds.co.uk/wp-content/uploads/article_files/V96/V96_N09/V96_N09_P439_446_A004.pdf