Hello Trevor,
Based on the figures I have seen posted by you and others, it seems that you are contemplating towing with a high ratio of over 90%.
I also note that you are new to towing, and these two facts together are of some concern. Most novice towers will start with a much lower towing ratio, and as they build their experience, they may feel able to handle higher ratio's,
But ratios alone do not determine if an outfit is good or bad. Many other factors come into play, and it is a broad range of characteristics that affect the tow-a-bility of an outfit.
The maximum permitted towed mass is set out by the vehicle manufacturer. This must not be exceeded along with the Gross Train Weight and axle loadings. Generally it is better to keep the overall weight of a trailer as low as possible. Some suggest only 85% though this has no legal bearing and is a guideline only.
The way the load is stored in the caravan will affect its towing. It is good practice to keep heavy items low down, and as near to the axle as possible.
The detailed disposition of the loaded items must be adjusted to create enough nose load to keep the outfit stable, but must not exceed the either the limit of the caravan hitch or the tow bar assembly on the car.
Don't forget that the trailers nose load is supported by the car, so this forms part of the cars paylaod. Don't over-load the car.
Good vehicle maintenance and tyre checks are also important.
One of the biggest contributing factors in instability is excessive speed. This is down to the driver, who must also read the road conditions ahead, and avoid sudden braking and changes of direction.
As Trevor has very succinctly said many people do tow quite safely with high figures, but in most cases they have gained years of experience which allows them to 'feel'the outfit and understand how to cope with it.