请教专家老师：

However, there is an even more insidious kind of pollution that particularly affects urban areas and invades our daily lives, and that is noise. Burglar alarms going off at any time of the day or night serve only to annoy passers-by and actually assist burglars to burgle. Car alarms constantly scream at us in the street and are a source of profound irritation. A recent survey of the effects of noise revealed (surprisingly?) that dogs barking incessantly in the night rated the highest form of noise pollution on a scale ranging from 1 to 7. The survey revealed a large number of sources of noise that we really dislike. Lawn mowers whining on a summer's day, late-night parties in apartment blocks, noisy neighbors, vehicles of al kinds, especially large container trucks thundering through quiet village, planes and helicopters flying overhead, large radios carried round in public places and played at maximum volume. New technology has also made its own contribution to noise. A lot of people object to mobile phones, especially when they are used in public places like restaurants or on public transport. Loud conversations on mobile phones invade our thoughts or interrupt the pleasure of meeting friends for a quiet chat. The noise pollution survey revealed a rather spurring and possibly amusing old fashioned source of noise. It turned out to be snoring! Men were found to be the worst offenders. It was revealed that 20% of men in their mid-thirties snore. This figure rises to a staggering 60% of men in their sixties. Against these figures, it was found that only 5% of women snore regularly, while the rest are constantly woken or kept awake by their trumpeting partners. Whatever the source of noise, one thing is certain: silence, it seems, has become a golden memory.

1）only to...这里是出乎意料之外的结果状语吗？谓语动词rated 感觉应该使用被动语态，即was rated才合理呀？

2）2个宾语从句中的谓语动词snore如果是正式语体都需要改成snored吧？谓语动词rises是一般现在时，所以，against these figures 中的figures是包括一般过去时中的20%和一般现在时中的60%？感到很难理解句意？

3）这一句 it was found that only 5% of women snore regularly, while the rest are constantly woken... 主句是过去式，而从句却是现在时，怎么理解含义呢？困惑。这种while（对比）是并列连词还是从属连词呢？