I ran your data through Lactate-E http://www.uiginn.com/lactate/lactate-e2.html. It’s free (if you have access to Excel) and based on a published paper…and pretty useful.
These are the values from the spreadsheet. I used a simple graphical method for estimating the thresholds.
I estimate between about 215-225 for LT1 and between about 265-270 for LT2.
Which values are the “correct” values is for you to determine. 
