Passenger numbers:
1971 - 136,000
1972 - 162,000
1973 - 212,000
2011 - 192,410
2012 - 166,251
2013 - 159,311 (plus maybe 1,500 in transit)
Given the loss of charters and assuming no major changes, one might expect DTV in 2014 to perform at roughly the same level as (or perhaps slightly better than) 1971, the year that the pound was decimalised.
Plymouth airport in 2009 had 157,933 passengers. In April 2011, Plymouth's owner published notice of airport closure.