So…………Given the change in observation techniques and frequencies...

So…………

Given the change in observation techniques and frequencies the comparison of readings between the two dates may be contentious.

Putting that aside it would appear that this year’s reading is virtually identical to the reading taken in 1967 or some 57 years ago.

So is the point you are trying to make is that nothing has really changed in the past 57 years because that would appear to be a very valid conclusion-well done!,