calculation of Cr 6.1 Stormwater design-Quantity Control

Thanks Mr. Hurst, Actually the data was given to me. Can you help me to verify the calculation of the storm. I only have a years rainfall data. I hope that's enough. Month Monthly Total mm Jan 11.9 Feb 17.8 Mar 23.7 Apr 32 May 49.9 Jun 232 Jul 326.5 Aug 346.1 Sep 239.1 Oct 86 Nov 11.2 Dec 3.1 Annual Total or Mean 1379.3 Thanks in advance.