How to draw trend lines to a time series data at different quartile?

Hi, I have annual time series data. How could I draw trend lines at different quartiles (0.25, 0.5, 0.75) of this data and obtain trend statistic for each line/quartile?

Here is example data:

Year index

2000 2.046

2001 2.051

2002 2.07

2003 2.075

2004 2.075

2005 2.055

2006 2.015

2007 2.038

2008 2.302

2009 2.215

2010 2.154

2011 2.108

2012 2.369

2013 3.236

2014 3.46

2015 3.582

[darova]

Do you have picture of how the result should looks like? Can you make a simple drawing?

[Parthu P]

Hi Darova,

I expect something like this

With trend statistic for each quartile. I also expect to alter these quartiles.

Thank you.

[darova]

Why are the lines not parallel?

[Parthu P]

This is an imaginary figure. The trend lines may be parallel or they might cross each other.

As these are not confidance levels, the lines are not parallel. Different quartiles/quantiles are expected to have different slope of the trend lines.

Thanks.