The measured soil water content of n = 12 samples of soil (where 3 replicates were taken at each of 4 different depths) is given in the following table, where soil water content is measured in cubic cm of water per cubic cm of soil.
Depth (cm) Soil Water Content
10 0.313 0.299 0.340
40 0.315 0.310 0.294
60 0.289 0.284 0.281
120 0.259 0.259 0.245
On the basis of this model, what can you say (in general) about the change in soil water content with increasing depth?