SBD (now known as SMD) is designed to represent less than 5% of the market cap of Steem at any time. Short term price changes (50% or 75% fall) could cause SMD to represent 10 or even 15% of the market cap of Steem.
STEEM supply, including the STEEM that backs VESTS (now known as SMP), will double every year. Every 3.32 years a 10:1 reverse STEEM split will occur.
The first year the supply of STEEM grows at a relatively constant rate (STEEM per minute) until the constant rate hits the minimum percentage rate.
VESTS is an accounting mechanism for a bucket of STEEM which will normally account for 90% of all STEEM . The number of VESTS does not matter because when they are created or redeemed holders of VESTS are never diluted in terms of VESTS.
Estimated supply after 1 year is 500M STEEM, it will grow to 5B over 3 years and then get split back to 500M.
For investors it is easiest to think in terms of "wealth reallocation" rather than in absolute number of shares. Only 10% of the STEEM market cap is reallocated per year (long term), of that reallocation half is in the form of Steem Dollars and half in the form of VESTS. This means that the vast majority of new STEEM is not entering the market. Most STEEM is created as a form of "stock split" which means those who hold VESTS see their quantity of STEEM increased by an amount sufficient to offset an fall in price.
RE: What is the current and projected supply of STEEM over time?