请问去年双边贸易额有多少？
二零一二年，双边贸易额为四点四九五八亿美元。[{'character': '二', 'pinyin': 'er4', 'highest pitch': 10.84, 'lowest pitch': 9.46, 'duration': 0.16, 'prosody hierarchy': 'null'}, {'character': '零', 'pinyin': 'ling2', 'highest pitch': 9.46, 'lowest pitch': 8.41, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '一', 'pinyin': 'i1', 'highest pitch': 10.75, 'lowest pitch': 9.08, 'duration': 0.15, 'prosody hierarchy': 'null'}, {'character': '二', 'pinyin': 'er4', 'highest pitch': 10.84, 'lowest pitch': 7.79, 'duration': 0.17, 'prosody hierarchy': 'null'}, {'character': '年', 'pinyin': 'nian2', 'highest pitch': 7.79, 'lowest pitch': 5.82, 'duration': 0.33, 'prosody hierarchy': '#3'}, {'pinyin': 'sp1', 'highest pitch': 0.0, 'lowest pitch': 0.0, 'duration': 0.1}, {'character': '双', 'pinyin': 'shuang1', 'highest pitch': 9.22, 'lowest pitch': 7.97, 'duration': 0.23, 'prosody hierarchy': 'null'}, {'character': '边', 'pinyin': 'bian1', 'highest pitch': 9.17, 'lowest pitch': 7.97, 'duration': 0.16, 'prosody hierarchy': '#1'}, {'character': '贸', 'pinyin': 'mao4', 'highest pitch': 8.67, 'lowest pitch': 7.39, 'duration': 0.16, 'prosody hierarchy': 'null'}, {'character': '易', 'pinyin': 'i4', 'highest pitch': 10.62, 'lowest pitch': 6.0, 'duration': 0.15, 'prosody hierarchy': 'null'}, {'character': '额', 'pinyin': 'e2', 'highest pitch': 7.81, 'lowest pitch': 5.57, 'duration': 0.33, 'prosody hierarchy': '#2'}, {'pinyin': 'sp1', 'highest pitch': 0.0, 'lowest pitch': 0.0, 'duration': 0.08}, {'character': '为', 'pinyin': 'uei2', 'highest pitch': 8.86, 'lowest pitch': 6.96, 'duration': 0.23, 'prosody hierarchy': '#2'}, {'character': '四', 'pinyin': 'sii4', 'highest pitch': 10.44, 'lowest pitch': 8.79, 'duration': 0.22, 'prosody hierarchy': 'null'}, {'character': '点', 'pinyin': 'dian3', 'highest pitch': 7.63, 'lowest pitch': 5.0, 'duration': 0.23, 'prosody hierarchy': '#1'}, {'character': '四', 'pinyin': 'sii4', 'highest pitch': 10.44, 'lowest pitch': 9.04, 'duration': 0.2, 'prosody hierarchy': 'null'}, {'character': '九', 'pinyin': 'jiou2', 'highest pitch': 9.44, 'lowest pitch': 7.15, 'duration': 0.19, 'prosody hierarchy': '#1'}, {'character': '五', 'pinyin': 'u3', 'highest pitch': 9.44, 'lowest pitch': 5.35, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '八', 'pinyin': 'ba1', 'highest pitch': 10.62, 'lowest pitch': 7.7, 'duration': 0.19, 'prosody hierarchy': 'null'}, {'character': '亿', 'pinyin': 'i4', 'highest pitch': 10.62, 'lowest pitch': 8.25, 'duration': 0.15, 'prosody hierarchy': '#1'}, {'character': '美', 'pinyin': 'mei3', 'highest pitch': 8.25, 'lowest pitch': 5.26, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '元', 'pinyin': 'van2', 'highest pitch': 6.53, 'lowest pitch': 5.08, 'duration': 0.35, 'prosody hierarchy': '#4'}]