By last six months, I assume that you mean Jan through June of 2015, and when you calculated the growth, it was based on YoY (Year over Year) comparing 1H (first half) of 2014 to 1H/15.
If that's the case, then revenue growth was nowhere near 400%.
Revenue (sales) for the first half of the fiscal year:
1H/14: $446.3K 2H/15: $1,178.8K
YoY Growth = 164%
FWIW, with 2H/14 revenues of $843.6K, when we calculate sequential growth (1H/15 v. 2H/14), it was 40%.