1/10,000 Sec, ISO 3071 
1/300 Sec, ISO 434 
1/100, ISO 50 
1/25 Sec, ISO 32 
1/15 Sec, ISO 25
It did take me some time to get the right moves to get the photos. Trying out different Secs and the ISO to get a different photo. The photos did come out with more light than with darkness as the sec and ISO went down.
You have good light to work with. It is interesting how at 1/15th of a second, it is too bright and your photo is overexposed.
In a case like this maybe move back from the window.