KDR lowers

Hello guys,

Yesterday I had a kdr of 1.49, but today it decreased to a 1.43. The thing is that I don't really get why it's decreasing, because I always end my day with a KDR higher than 1.70 and such.
If there is someone that have a vague idea about it and at least can explain somehow to me why this is happening, I would be really happy haha.