Splunk alert base on current count vs last week count

[cbiraris]

Hi Team,

I need help to create a alert which can raise if latest hour count is 10% less than last week same day same hour count.  

for example: right now i can able to get count but not sure how to find  10%  or more difference to get alert.

 index=ABC sourcetype=XYZ | timechart span=1h count | timewrap d series=short 

[ITWhisperer]

| eval change=100*(s0-s7)/s7