NEW YORK — A report by environmental group Oceana has found that plastic waste from Amazon packages went up by 18% last year, but Amazon says it has reduced its use of single-use plastic across its network. According to the Oceana’s estimates, released Thursday, Amazon’s plastic waste jumped from 599 million pounds in 2020 to 709 million pounds last year — an amount that can circle the planet more than 800 times in the form of air pillows, the group said. That idea was put up for a vote two times at Amazon’s annual shareholders meetings during the past two years.