The production of United States aerograms has ceased. The US issued a total of 25 aerograms through 1999. But for aerograms, those terms are misleading. Sales of aerograms in the United States ended in 2006 due to poor sales. Not all lettersheets are aerograms, however. Most aerograms have an imprinted stamp indicating the prepayment of postage. Countries such as New Zealand, Zimbabwe and Ireland, have printed unstamped aerograms. However, some countries such as New Zealand, Zimbabwe and Ireland, sell unstamped aerograms. With the decline in postal communication, Aerograms have been withdrawn from various postal services.