求助！帮帮翻译一下几个句子和解决一道蓝皮书上的题～～

loisinbeijing

1 Technically a given category of insurance policy is underpriced if, over time, claims against it plus expenses associated with it exceed total income from premiums.
2 Prices are lower outside of Canada in large part because the goods-and-services tax that pays for Canadian social services is not applied.
3 还有一道加强题 the total market value of real estate in Altonvile has steadily declined over the past four years. This decline has meant that the overall figure on which the city's property tax is based-- the assessed value of that real estate-- has also declined. The percentage of assessed value that was paid as property taxes to the city, however, did not change from year to year during this period. 这道题后面没弄懂啊 是什么percentage?  答案是 the amount of revenue that Altonvile collected from property taxes was lower last year than it was four years ago.
谢谢！！！