Does the ratio of daylight change from year to year? Over a year, the ratio of daylight changes, e.g. in Montreal there is more daylight in the summer than in the winter.

I want to know if, given a bad data sample, e.g. five years, one might notice a trend of increasing or decreasing daylight ratios.

Here's why I ask. I'm doing research on the Dead Sea scrolls, and some of the fragments contain ratios that a scholar has argued represent daylight. What I'd like to know is a trend that the community of Qumran might have noticed in their dataset. They had a theory that darkness was increasing. I doubt their data was exhaustive, but I wonder if around Jerusalem there might have been a period of decreasing daylight ratios over a period of a few years roughly around 100 B.C.E.
I don't think it's possible to have a change in the ratio of day to night when averaged on a yearly basis.  To do so would require either a nonlinear change in the Earth's rotation or a significant shift in the polar axis tilt within a year.
If the rotation were simply slowing down over time, the year-averaged ratio would be the same every year (only the number of days in a year would change).  Similarly, the only way a polar tilt could cause a change would be if the change in angle occurred at some (sinusoidal) rate not an integral ratio of the orbital period (year).
Either of those putative mechanisms can only change the per-year ratio by producing a day/night ratio in "summer" that is not the inverse of the "winter" ratio, and producing a different non-inverse the following year.  (I'm oversimplifying a bit, since the elliptic orbit produces a repeatable asymmetry in the Sun's zenith pattern).