Applying Symbology to layer through ArcPy script and values are getting changed?

Question

I am doing a raster calculation over a hdf file and after that i have to apply symbology on it.When i am applying Symbology to the raster layer through script .its values get changed as compared to the values i am geting when i am doing it manually . Symbology Type : Stretched

script i am using is as ...

import arcpy
from arcpy.sa import *
env.workspace = "E:\data"
arcpy.CheckOutExtension("Spatial")
in_layer ="E:\data\filename.hdf"

#raster calculation

output= floatdivide(in_layer,10000)

# applying symbology

lyr ="output"
symbolLyr = r"E:\data\Layer.lyr"
arcpy.ApplySymbologyFromLayer_management(lyr, symbolLyr)

Applying Script changes the topmost 3 values and changed it to the Min value ,Avg Value and Max Value , As Shown in Screen shot 1.. Max Value : 0.997 , Avg Value : 0.3985, Min Value :-0.2.

In Screen shot 2 we can see the first three values are changed.

Screenshot for Process by Arcpy Script

Screenshot for Manual Process