With experience, the defenders improved their effectiveness: in Christmas week, the Antwerp X defences plotted 209 missiles approaching the city, of which 171 came from directions in which it was safe to employ AA guns; of these 102 were engaged and 61 destroyed. The number of V-1s approaching Antwerp reached a peak of 623 a week in February, but declined thereafter. Overall the defenders' success rate was 43.2 per cent of V-1s destroyed by AA fire, reaching 97.5 per cent in March, after which the launch sites in Germany were overrun.