The term last year defines last year according to calender.So if I say last year in 2014, it means I refer to 2013.
On the other hand, the term last one year refers to last 12 months.So if I use this term in mar 2014, it refers to period between mar2013-feb2014.
Am I right on this? Can you explain what the following two sentences mean?
I am actively participating since last year.
I am actively participating for last one year.