We have had 4 break-ins or attempted break ins. The first two times we had windows securely locked, but in one case a window was jemmied. The second time the miscreant worked there way round the house breaking ground floor sash windows until he found one where he could get in without cutting himself.
We then put in a ground floor alarm in a tall, high ceilinged Victorian semi, overlooking a very busy traffic light controlled junction that our house dominated like a light house.
Third time, at around 8.00pm on a light bright summer Saturday evening someone climbed a drain pipe at the front of the house, inched his way along the front of the house at first floor level using a narrow (+/- 4 inches) decorative noggin to get to the middle window of three large sash windows, which had been left open about one inch, pulled the sash down and climbed in. All in full sight of all the traffic at the traffic lights. After scouting around upstairs and finding nothing worth stealing, he went downstairs, set the alarm off - and scarpered.
When the police came, despite the window being wide open and there being trainer prints on the window sill and radiator the police refused to believe the intruder had got in that way. It was only when they had inspected every other window and door in the house and found them locked tight and untouched that they finally accepted what had actually happened - and they were completely gobsmacked. It was the talk of the police staion for a week and, I was told, a lot of the police members, drove past our house just to see how gobsmacking it was!
Last time was over 25 years ago when we moved to our current house. Someone jemmied a window - and the burglar alarm went off, and, again, the burglars scarpered.
In three of these four events, the cost of repairing windows cost more than what was lost. No money in the house, no jewellry. nothing readily saleable. The first one I lost all my jewellry - such as it was, mainly silver braclets. Even today the value of what I lost was well under £1,000.