TPS92512HV: Output current is varying by 6-7%

Hello,

I have designed LED driver circuit using TPS92512. My requirement is to drive LED with constant current of  535mA at the minimum input of 44V (Typical:48V).

I have LED's with 6.5V of forward voltage drop at 535mA. While testing I observe that current flowing through LED's are on higher side i.e. 570mA and it is varying board to board by 5-6mA  

I have used shunt resistor with 1% tolerance and applied 48V constant voltage for all boards. I have followed all layout guidelines as recommended in datasheet

Why output current is not coming as per expectation? error in output current is almost 6-7%

Please find reference schematic given below

Thanks in advance for your support!!!