Help histogram and range

[salvomic]

hi, please, can someone help me with this statistic in Statistics 1var?

I've four classes of values:
1000÷1500, 1500 ÷ 2000, 2000 ÷ 2500, 3000 ÷ 3500
with these frequencies:
1, 3, 4, 12
I put the center values:
1250, 1750, 2250, 3250 in D1 and the frequencies in D2
I set Plot setup:
H width 500, H range 0 ÷ 12, X range 1000 ÷ 4000, Y range -10 ÷15, X tick 500, Y tick 5
But I cannot see any histogram...

If I divide values x 1000 (or 100) I see them...

Where I'm wrong?
Thank you

Salvo