I came across your question and hopefully my answer will help?
Based upon the information that you provided I ve place some figures down below:
Grade of Service .1= 36 trunks
Grade of Service .2= 33 trunks
Grade of service .3= 32 trunks
Grade of service is the blockage precentage that your company set with your carrier. When trying to figure out how many T1’s you might need you will need to know correct grade of service.