measure drop in values

[sqoo]

Hello,
I am sorry if this was mentioned already somewhere else, but i have no clue how to call the thing i am looking for, so no idea how to search for it. Basically i have a table with prices over period with growing trend. I would like to measure (if you imagine uptrending graph) length and strength of price drops - how many days until price gets back to previous high and what was the lowest price during this price drop period.
graph.png

[Vikas_Gautam]

Need an excel file having that table you are talking about..