How to write a simple working "less than or equal" sentence in lovelace?

I have a house plan I created with Floorplan years ago, writting it in yaml. Now I added a bluetooth moisture plant sensor, and I want to see different images on the plan depending on sensor value.
I get it working for fixed vale, let’s say 38% moisture… it works fine with this code

  • type: image
    entity: sensor.plant_sensor_97_moisture
    tap_action:
    action: none
    state_image:
    ‘38’: /local/Floorplan/Water.png

    This show Water.png image, when the sensor value is exactly 38. But, what I really want is get the water image when the sensor value be less (or even equal, but less will be fine) than 38. I tried with “‘<=38’: /local/Floorplan/Water.png” and “‘<=38’: /local/Floorplan/Water.png” but none works.

Which could be the right way to write “less than 38”?

A workaround would be to create a template binary sensor in configuration.yaml - then you’d have a simple on/off condition for Lovelace.