average cost per annum

• 年平均费用

average cost per annum的用法和样例：

例句

1. The average monthly tab comes to $168.50.
   每月平均费用达到一百六十八点五美元。
2. In any case, even as the CME has grown rapidly in recent years, it has steadily lowered the average fee it charges per contract.
   不管怎样，甚至当芝加哥商业交易所在最近几年内快速增长的时候，它也稳定地降低对每个合约所收取的平均费用。